Hole transporting polymer and organic electroluminescence device using the same

ABSTRACT

A hole transporting polymer including a repeating unit represented by one of formulas (1) and (5):It can exhibit an excellent hole transporting property and exhibits superior durability and film-forming properties. An organic EL device using this hole transporting polymer has excellent light emitting characteristics.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a hole transporting polymer, a methodof producing the same, and an organic electroluminescence device(hereinafter referred to as an “organic EL device”, sometimes) using thehole transporting polymer.

2. Description of the Related Art

An inorganic electroluminescence device (hereinafter referred to as an“inorganic EL device”, sometimes) using an inorganic fluorescentsubstance has hitherto been used for a flat light source as backlight, adisplay device such as flat panel display or the like, but ahigh-voltage alternating current was required for driving the devices.

Tang et al. have recently fabricated an organic EL device having atwo-layer structure, comprising a laminate of a light emitting layer ofan organic fluorescent dyes and a layer of an organic chargetransporting compound generally used in a photosensitive layer forelectrophotography (U.S. Pat. No. 4,539,507). Since the organic ELdevice has a feature that emission of various colors can be easilyobtained, in addition to low-voltage driving and high luminance, incomparison with the inorganic EL device, various attempts have been madeand reported regarding the development and improvement of the devicestructure, organic fluorescent dyes and organic charge transportingcompounds, etc [Jpn. J. Appl. Phys. Vol. 27, page L269 (1988); and J.Appl. Phys., Vol. 65, page 3610 (1989)]

As the hole transporting material, for example, various compounds suchas oxadiazole derivatives, oxazol derivatives, hydrazone derivatives,triarylpyrazoline derivatives, arylamine derivatives, stilbenederivatives and the like have been reported.

In case of using only a low molecular weight hole transporting materialin the organic EL device, the mechanical strength and heat resistance ofthe hole transporting layer were insufficient. As the method of forminga hole transporting layer, deposition under vacuum is generally used buthas a problem of high production cost. To the contrary, there have beenreported a lot of examples using the hole transporting polymer, such asorganic EL device using a polystyrene derivatives having an aromaticamine group on the side chain (JP-A-8-259935), organic EL device using apolyester having an aromatic amine group(JP-A-8-259880) and the like,for the purpose of improving the durability and film-forming property.However, these organic EL devices are not necessarily satisfactory inview of the stability on driving.

On the other hand, in a photosensitive layer for electrophotographyusing the hole transporting material, like the organic EL device, theaddition of a polysiloxane is performed for the purpose of preventingdeterioration caused by corona discharge. Furthermore, there has beenreported a hole transporting polysiloxane obtained by mixing a siliconhole transporting material with a curable polysiloxane and curing themixture for the purpose of imparting the hole transporting property tothe polysiloxane (JP-A-9-124943).

As an example of using a hole transporting polysiloxane in an organicEL, an organic EL device obtained by mixing a polysiloxane having acarbazole group on the side chain with a light emitting polymer has beenproposed (WO 9501871).

SUMMARY OF THE INVENTION

An object of the present invention is to provide a hole transportingpolymer having excellent hole transporting property, excellentdurability and excellent film-forming property, and a method ofproducing the same, and an organic EL device having excellent lightemitting characteristics, using the hole transporting polymer.

The present inventors have intensively studied to solve these problems,and found that a specific novel hole transporting polymer has excellenthole transporting property, excellent durability and excellentfilm-forming property, and that an organic EL device prepared by usingthe hole transporting polymer has excellent light emittingcharacteristics. Thus, the present invention has been accomplished.

SUMMARY OF THE INVENTION

That is, the present invention relates to [1] a hole transportingpolymer comprising a repeating structural unit represented by thefollowing general formula (1), and having a polystyrene-reducednumber-average molecular weight of from 10³ to 10⁷:

wherein R₁ represents an alkyl group having 1 to 20 carbon atoms, acycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to30 carbon atoms or an aralkyl group having 7 to 32 carbon atoms; Ar₁represents an arylene group having 6 to 30 carbon atoms, or an aryleneethenylene group represented by the following general formula (2); Ar₂and Ar₃ independently represent an aryl group having 6 to 30 carbonatoms, an aromatic amine group represented by the following generalformula (3), or an arylene ethenylene group represented by the followinggeneral formula (4); and a ring may be formed between Ar₁ and Ar₂, orAr₁ and Ar₃, or Ar₂ and Ar₃:

wherein Ar₄ and Ar₅ independently represent an arylene group having 6 to30 carbon atoms; R₂ and R₃ independently represent hydrogen atom, analkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to20 carbon atoms, an aryl group having 6 to 30 carbon atoms or an aralkylgroup having 7 to 32 carbon atoms:

wherein Ar₆ represents an arylene group having 6 to 30 carbon atoms; R₄and R₅ independently represent an alkyl group having 1 to 20 carbonatoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl grouphaving 6 to 30 carbon atoms or an aralkyl group having 7 to 32 carbonatoms; and a ring may be formed between Ar₆ and R₄, or Ar₆ and R₅, or R₄and R₅:

wherein Ar₇ represents an arylene group having 6 to 30 carbon atoms; R₆and R₇ independently represent hydrogen atom, an alkyl group having 1 to20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an arylgroup having 6 to 30 carbon atoms or an aralkyl group having 7 to 32carbon atoms; Ar₈ represents an aryl group having 6 to 30 carbon atoms.

The present invention also relates to [2] a hole transporting polymercomprising a repeating structural unit represented by the followinggeneral formula (5), and having a polystyrene-reduced number-averagemolecular weight of from 10³ to 10⁷:

wherein Ar₉ and Ar₁₁ independently represent an arylene group having 6to 30 carbon atoms, an aromatic amine group represented by the followinggeneral formula (6) or an arylene ethenylene group represented by thefollowing general formula (7); Ar₁₀ represents an aryl group having 6 to30 carbon atoms, an aromatic amine group represented by the followinggeneral formula (8) or an arylene ethenylene group represented by thefollowing general formula (9); a ring may be formed between Ar₉ andAr₁₀, or Ar₉ and Ar₁₁, or Ar₁₀ and Ar₁₁; and R₈, R₉, R₁₀ and R₁₁independently represent hydroxy group, an alkyl or alkoxy group having 1to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, anaryl group having 6 to 30 carbon atoms or an aralkyl group having 7 to32 carbon atoms, a group represented by the following general formula(10) or (12), or divalent oxygen atom which may be bonded to anintramolecular silicon atom by crosslinking or to a silicon atom in themolecule vicinally sited by crosslinking:

wherein Ar₁₂ and Ar₁₃ independently represent an arylene group having 6to 30 carbon atoms; R₁₂ represents an alkyl group having 1 to 20 carbonatoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl grouphaving 6 to 30 carbon atoms or an aralkyl group having 7 to 32 carbonatoms; and a ring may be formed between Ar₁₂ and Ar₁₃, or Ar₁₂ and R₁₂,or Ar₁₃ and R₁₂:

wherein Ar₁₄ and Ar₁₅ independently represent an arylene group having 6to 30 carbon atoms; and R₁₃ and R₁₄ independently represent hydrogenatom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl grouphaving 3 to 20 carbon atoms, an aryl group having 6 to 30 carbon atomsor an aralkyl group having 7 to 32 carbon atoms:

wherein Ar₁₆ represents an arylene group having 6 to 30 carbon atoms;R₁₅ and R₁₆ independently represent an alkyl group having 1 to 20 carbonatoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl grouphaving 6 to 30 carbon atoms or an aralkyl group having 7 to 32 carbonatoms; and a ring may be formed between Ar₁₆ and R₅₁, or Ar₁₆ and R₁₆,or R₁₅ and R₁₆):

wherein Ar₁₇ represents an arylene group having 6 to 30 carbon atoms;R₁₇ and R₁₈ independently represent hydrogen atom, an alkyl group having1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, anaryl group having 6 to 30 carbon atoms or an aralkyl group having 7 to32 carbon atoms; and Ar₁₈ represents an aryl group having 6 to 30 carbonatoms:

wherein Ar₁₉ and Ar₂₁ independently represent an arylene group having 6to 30 carbon atoms, an aromatic amine group represented by the abovegeneral formula (6) or an arylene ethenylene group represented by theabove general formula (7); Ar₂₀ represent an aryl group having 6 to 30carbon atoms, an aromatic amine group represented by the above generalformula (8) or an arylene ethenylene group represented by the abovegeneral formula (9); and a ring may be formed between Ar₁₉ and Ar₂₀, orAr₁₉ and Ar₂₁, or Ar₂₀ and Ar₂₁; R₁₉ and R₂₀ independently representhydroxy group, an alkyl or alkoxy group having 1 to 20 carbon atoms, acycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to30 carbon atoms or an aralkyl group having 7 to 32 carbon atoms, ordivalent oxygen atom which may be bonded to an intramolecular siliconatom by crosslinking or to a silicon atom in the molecule vicinallysited by crosslinking; R₂₁ represents hydrogen atom or a grouprepresented by the following general formula (11):

wherein R₂₂, R₂₃ and R₂₄ independently represent hydroxy group, an alkylgroup or alkoxy group having 1 to 20 carbon atoms, a cycloalkyl grouphaving 3 to 20 carbon atoms, an aryl group having 6 to 30 carbon atomsor an aralkyl group having 7 to 32 carbon atoms:

wherein R₂₅, R₂₆ and R₂₇ independently represent an alkyl group having 1to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, anaryl group having 6 to 30 carbon atoms or an aralkyl group having 7 to32 carbon atoms, or an arylene ethenylene group represented by the abovegeneral formula (9) or an aromatic amine group represented by thefollowing general formula (13):

wherein Ar₂₂ represents an arylene group having 6 to 30 carbon atoms, anaromatic amine group represented by the above general formula (6) or anarylene ethenylene group represented by the above general formula (7);Ar₂₃ and Ar₂₄ independently represent an aryl group having 6 to 30carbon atoms, an aromatic amine group represented by the above generalformula (8) or an arylene ethenylene group represented by the abovegeneral formula (9).

The present invention also relates to [3] the hole transporting polymeraccording to [2], wherein the compound group represented by the abovegeneral formula (12) is in an amount of from 10% by mole to 150% by molebased on the total silicon atoms belonging to said hole transportingpolymer except silicon atoms contained in said compound group, and thecontent of the hydroxyl group is less than 10% by mole based on thetotal silicon atoms belonging to said hole transporting polymer exceptsilicon atoms contained in said compound group.

The present invention also relates to [4] a method of producing a holetransporting polymer of [1], wherein at least one silane compoundrepresented by the following general formula (14) is hydrolyzed andcondensed:

wherein X represents a halogen atom or an alkoxy group having 1 to 20carbon atoms; R₁, Ar₁, Ar₂ and Ar₃ are as defined in [1]; and a ring maybe formed between Ar₁ and Ar₂, or Ar₁ and Ar₃, or Ar₂ and Ar₃.

The present invention also relates to [5] the method of producing a holetransporting polymer of [2], wherein at least one silane compoundrepresented by the following general formula (15), or a mixture of atleast one silane compound represented by the following general formula(15) and at least one silane compound represented by the followinggeneral formula (16) is hydrolyzed and condensed.

wherein R₃₀, R₃₁, R₃₂ and R₃₃ independently represent a halogen atom, analkyl group or alkoxy group having 1 to 20 carbon atoms, a cycloalkylgroup having 3 to 20 carbon atoms, an aryl group having 6 to 30 carbonatoms or an aralkyl group having 7 to 32 carbon atoms; R₂₈ and R₂₉independently represent hydroxy group or an alkoxy group having 1 to 20carbon atoms; Ar₂₅ and Ar₂₇ are the same with Ar₉ as defined in thegeneral formula (5) of [2] or Ar₁₉ as defined in the general formula(10) of [2]; Ar₂₆ is the same with Ar₁₀ as defined in the generalformula (5) of [2]; and a ring may be formed between Ar₂₅ and Ar₂₆, orAr₂₅ and Ar₂₇, or Ar₂₆ and Ar₂₇:

wherein R₃₅ and R₃₆ independently represent a halogen atom, an alkylgroup or alkoxy group having 1 to 20 carbon atoms, a cycloalkyl grouphaving 3 to 20 carbon atoms, an aryl group having 6 to 30 carbon atomsor an aralkyl group having 7 to 32 carbon atoms; R₃₄ represents ahalogen atom, an alkoxy group having 1 to 20 carbon atoms; Ar₂₈represents an arylene group having 6 to 30 carbon atoms or an aryleneethenylene group represented by the following general formula (17); Ar₂₉and Ar₃₀ independently represent an aryl group having 6 to 30 carbonatoms, an aromatic amine group represented by the following generalformula (18) or an arylene ethenylene group represented by the followinggeneral formula (19); and a ring may be formed between Ar₂₈ and Ar₂₉, orAr₂₈ and Ar₃₀, or Ar₂₉ and Ar₃₀:

wherein Ar₃₁ and Ar₃₂ independently represent an arylene group having 6to 30 carbon atoms; R₃₇ and R₃₈ independently represent hydrogen atom,an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms or anaralkyl group having 7 to 32 carbon atoms:

wherein Ar₃₃ represents an arylene group having 6 to 30 carbon atoms;R₃₉ and R₄₀ independently represent an alkyl group having 1 to 20 carbonatoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl grouphaving 6 to 30 carbon atoms or an aralkyl group having 7 to 32 carbonatoms; and a ring may be formed between Ar₃₃ and R₃₉, or Ar₃₃ and R₄₀,or R₃₉ and R₄₀:

wherein Ar₃₄ represents an arylene group having 6 to 30 carbon atoms;R₄₁ and R₄₂ independently represent hydrogen atom, an alkyl group having1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, anaryl group having 6 to 30 carbon atoms or an aralkyl group having 7 to32 carbon atoms; and Ar₃₅ represents an aryl group having 6 to 30 carbonatoms.

The present invention also relates to [6] the method of producing a holetransporting polymer of [2] or [3], wherein the hole transportingpolymer obtained by [5] is reacted with the compound represented by thefollowing general formula (20),

wherein X represents a halogen atom or an alkoxy group having 1 to 20carbon atoms; R₂₅, R₂₆, and R₂₇ are as defined in the general formula(12).

The present invention also relates to [7] an organic electroluminescencedevice comprising a pair of electrodes of an anode and a cathode, atleast one of which is transparent or semitransparent, and at least onelayer of an organic material formed between the electrodes, wherein theorganic material layer contains the hole transporting polymer describedin any one of [1] to [3].

The present invention also relates to [8] an organic electroluminescencedevice comprising a pair of electrodes of an anode and a cathode, atleast one of which is transparent or semitransparent, and a lightemitting layer formed between the electrodes, wherein the light emittinglayer contains the hole transporting polymer described in any one of [1]to [3].

The present invention also relates to [9] an organic electroluminescencedevice comprising a pair of electrodes of an anode and a cathode, atleast one of which is transparent or semitransparent, and a lightemitting layer formed between the electrodes, wherein a holetransporting layer containing the hole transporting polymer described inany one of [1] to [3] is provided adjacent to the light emitting layerbetween the anode and the light emitting layer.

The present invention also relates to [10] the organicelectroluminescence device according to [8] or [9], wherein an electrontransporting layer containing an electron transporting compound isprovided adjacent to the light emitting layer between the anode and thelight emitting layer.

The present invention also relates to [11] the organicelectroluminescence device according to any one of [8] to [10], whereinthe light emitting layer contains a light emitting polymer, whichcontains a repeating structural unit represented by the followinggeneral formula (21) in the proportion of 50% by mol or more based onthe total repeating structural units and has a polystyrene-reducednumber-average molecular weight of 10³ to 10⁷,

—Ar—CR═CR′  (21)

wherein Ar represents an arylene group or heterocylic compound grouphaving 4 to 20 carbon atoms, which take part in a conjugated bond; and Rand R′ independently represent a group selected from the groupconsisting of hydrogen atom, alkyl group having 1 to 20 carbon atoms,aryl group having 6 to 20 carbon atoms, heterocyclic compound having 4to 20 carbon atoms and cyano group.

DETAILED DESCRIPTION OF THE INVENTION

The first hole transporting polymer of the present invention is a holetransporting polymer containing a repeating structural unit representedby the above general formula (1), and having a polystyrene-reducednumber-average molecular weight of from 10³ to 10⁷. In view of the filmforming property, the polystyrene-reduced number-average molecularweight is preferably from 10³ to 10⁶.

In the general formula (1), R₁ is a straight-chain or branched alkylgroup having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20carbon atoms, an aryl group having 6 to 30 carbon atoms or an aralkylgroup having 7 to 32 carbon atoms, preferably a straight-chain orbranched alkyl group having 1 to 10 carbon atoms, a cycloalkyl grouphaving 3 to 10 carbon atoms, an aryl group having 6 to 20 carbon atomsor an aralkyl group having 7 to 22 carbon atoms, and more preferably astraight-chain or branched alkyl group having 1 to 6 carbon atoms or acycloalkyl group having 3 to 6 carbon atoms.

Specific examples of R₁ include alkyl group such as methyl group, ethylgroup, n-propyl group, isopropyl group, n-butyl group, sec-butyl group,tert-butyl group, pentyl group, hexyl group, heptyl group, octyl groupor the like; cycloalkyl group such as cyclopropyl group, cyclobutylgroup, cyclopentyl group, cyclohexyl group or the like; aryl group suchas phenyl group, naphthyl group, anthryl group, biphenyl group or thelike, which may be substituted with methyl group, ethyl group, propylgroup; and aralkyl group such as benzyl group, phenethyl group and thelike, which may be substituted with methyl group, ethyl group, propylgroup.

In the general formula (1), the arylene group for Ar₁ is an arylenegroup having 6 to 30 carbon atoms, preferably an arylene group having 6to 20 carbon atoms, and more preferably a phenylene, naphthylene oranthrylene group which may be substituted with a straight-chain orbranched alkyl group having 1 to 6 carbon atoms or a cycloalkyl grouphaving 3 to 6 carbon atoms.

Specific examples of the arylene group for Ar, include phenylene group,naphthylene group, anthrylene group and the like, which may besubstituted with methyl group, ethyl group or propyl group.

In addition, Ar₁ in the general formula (1) may be an arylene ethenylenegroup represented by the above general formula (2). In the generalformula (2), Ar₄ and Ar₅ are independently an arylene group having 6 to30 carbon atoms, preferably an arylene group having 6 to 20 carbonatoms, and more preferably a phenylene group which may be substitutedwith a straight-chain or branched alkyl group having 1 to 6 carbon atomsor a cycloalkyl group having 3 to 6 carbon atoms.

Specific examples of Ar₄ and Ar₅ independently include phenylene group,naphthylene group, anthrylene group and the like, which may besubstituted with methyl group, ethyl group or propyl group.

In the general formula (2), R₂ and R₃ are independently hydrogen atom, astraight-chain or branched alkyl group having 1 to 20 carbon atoms, acycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to30 carbon atoms or an aralkyl group having 7 to 32 carbon atoms,preferably hydrogen atom, a straight-chain or branched alkyl grouphaving 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbonatoms, an aryl group having 6 to 20 carbon atoms or an aralkyl grouphaving 7 to 22 carbon atoms, and more preferably hydrogen atom, astraight-chain or branched alkyl group having 1 to 6 carbon atoms, or aphenylene group which may be substituted with a straight-chain orbranched alkyl group having 1 to 6 carbon atoms or a cycloalkyl grouphaving 3 to 6 carbon atoms.

Specific examples of R₂ and R₃ independently include hydrogen atom,methyl group, ethyl group, propyl group, or a phenyl group which may besubstituted with methyl group, ethyl group, propyl group.

In the general formula (1), the aryl group for Ar₂ and Ar₃ areindependently an aryl group having 6 to 30 carbon atoms, preferably anaryl group having 6 to 20 carbon atoms, and more preferably a phenyl ornaphthyl group which may be substituted with a straight-chain orbranched alkyl group having 1 to 6 carbon atoms or a cycloalkyl grouphaving 3 to 6 carbon atoms.

Specific examples of the aryl group for Ar₂ and Ar₃ independentlyinclude phenyl group, naphthyl group, anthryl group and the like, whichmay be substituted with methyl group, ethyl group or propyl group.

In addition, Ar₂ and Ar₃ in the general formula (1) may be independentlyan aromatic amine group represented by the general formula (3). In thegeneral formula (3), Ar₆ is an arylene group having 6 to 30 carbonatoms, preferably an arylene group having 6 to 20 carbon atoms, and morepreferably a phenylene or biphenylene group which may be substitutedwith a straight-chain or branched alkyl group having 1 to 6 carbon atomsor a cycloalkyl group having 3 to 6 carbon atoms.

Specific examples of Ar₆ include phenylene group, naphthylene group,anthrylene group, biphenylene group and the like, which may besubstituted with methyl group, ethyl group or propyl group.

In the general formula (3), R₄ and R₅ are independently a straight-chainor branched alkyl group having 1 to 20 carbon atoms, a cycloalkyl grouphaving 3 to 20 carbon atoms, an aryl group having 6 to 30 carbon atomsor an aralkyl group having 7 to 32 carbon atoms, preferably astraight-chain or branched alkyl group having 1 to 10 carbon atoms, acycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to20 carbon atoms or an aralkyl group having 7 to 22 carbon atoms, andmore preferably a phenyl or naphthyl group which may be substituted witha straight-chain or branched alkyl group having 1 to 6 carbon atoms or acycloalkyl group having 3 to 6 carbon atoms.

Specific examples of R₄ and R₅ independently include phenyl group,naphthyl group, anthryl group, biphenyl group and the like, which may besubstituted with methyl group, ethyl group or propyl group.

In the general formula (3), a ring may be formed between Ar₆ and R₄, Ar₆and R₅, or R₄ and R₅.

In addition, Ar₂ and Ar₃ in the general formula (1) may be independentlyan arylene ethenylene group represented by the general formula (4). Inthe general formula (4), Ar₇ is an arylene group having 6 to 30 carbonatoms, preferably an arylene group having 6 to 20 carbon atoms, and morepreferably a phenylene group which may be substituted with astraight-chain or branched alkyl group having 1 to 6 carbon atoms or acycloalkyl group having 3 to 6 carbon atoms.

Specific examples of Ar₇ include phenylene group, naphthylene group,anthrylene group and the like, which may be substituted with methylgroup, ethyl group or propyl group.

In the general formula (4), Ar₈ is an aryl group having 6 to 30 carbonatoms, preferably an aryl group having 6 to 20 carbon atoms, and morepreferably a phenyl group which may be substituted with a straight-chainor branched alkyl group having I to 6 carbon atoms or a cycloalkyl grouphaving 3 to 6 carbon atoms.

Specific examples of Ar₈ include phenyl group, naphthyl group, anthrylgroup and the like, which may be substituted with methyl group, ethylgroup or propyl group.

In the general formula (4), R₆ a nd R₇ are independently hydrogen atom,a straight-chain or branched alkyl group having 1 to 20 carbon atoms, acycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to30 carbon atoms or an aralkyl group having 7 to 32 carbon atoms,preferably hydrogen atom, a straight-chain or branched alkyl grouphaving 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbonatoms, an aryl group having 6 to 20 carbon atoms or an aralkyl grouphaving 7 to 22 carbon atoms, and more preferably hydrogen atom, astraight-chain or branched alkyl group having 1 to 6 carbon atoms, or aphenyl group which may be substituted with a straight-chain or branchedalkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to6 carbon atoms.

Specific examples of R₆ and R₇ independently include hydrogen atom,methyl group, ethyl group, propyl group, or phenyl group which may besubstituted with methyl group, ethyl group or propyl group.

In the general formula (1), a ring may be formed between Ar₁ and Ar₂,Ar, and Ar₃, or Ar₂ and Ar₃.

The first hole transporting polymer may be a copolymer as long as itcomprises a repeating structural unit represented by the general formula(1). Examples of other copolymerisable repeating structural unit includea repeating structural unit represented by the following general formula(22). Examples of the copolymer include copolymers containing therepeating structural unit represented by the general formula (1) and atleast one kind of repeating structural unit represented by the followinggeneral formula (22). The composition of the copolymer is notspecifically limited as long as the properties of the hole transportingpolymer are not deteriorated. The proportion of the repeating structuralunit represented by the general formula (1) based on the total of therepeating units is usually 20-100% by mole and preferably 50-100% bymole.

wherein R″s represent an alkyl or aryl group having 1 to 12 carbonatoms, which may be the same or different.

The second hole transporting polymer of the present invention is a holetransporting polymer containing a repeating structural unit representedby the above general formula (5), and having a polystyrene-reducednumber-average molecular weight of from 10³to 10⁷. In view of the filmforming property, the polystyrene-reduced number-average molecularweight is preferably from 10³ to 10⁶.

The second hole transporting polymer may be a copolymer which contains arepeating structural unit other than the repeating unit represented bythe general formula (5) as long as the properties of the holetransporting polymer are not deteriorated. Examples of othercopolymerisable repeating structural unit include a repeating structuralunit represented by the above general formula (22). The proportion ofthe repeating structural unit represented by the general formula (5)based on the total of the repeating units is usually 20-100% by mole andpreferably 50-100% by mole.

In the general formula (5), R₈, R₉, R₁₀ or R₁₁ is independently hydroxygroup, a straight-chain or branched alkyl or alkoxy group having 1 to 20carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an arylgroup having 6 to 30 carbon atoms or an aralkyl group having 7 to 32carbon atoms, a group represented by the general formula (10), a grouprepresented by the general formula (12), or divalent oxygen atom whichmay be bonded to an intramolecular silicon atom by crosslinking or to asilicon atom in the molecule vicinally sited by crosslinking, preferablyhydroxy group, a straight-chain or branched alkyl or alkoxy group having1 to 10 carbon atoms or a cycloalkyl group having 3 to 10 carbon atoms,a group represented by the general formula (10), a group represented bythe general formula (12), or divalent oxygen atom which may be bonded toan intramolecular silicon atom by crosslinking or to a silicon atom inthe molecule vicinally sited by crosslinking, and more preferablyhydroxy group or a straight-chain or branched alkyl or alkoxy grouphaving 1 to 6 carbon atoms, a group represented by the general formula(10), a group represented by the general formula (12), or divalentoxygen atom which may be bonded to an intramolecular silicon atom bycrosslinking or to a silicon atom in the molecule vicinally sited bycrosslinking.

Specific examples of R₈, R₉, R₁₀ or R₁₁ independently include hydroxygroup; an alkyl group such as methyl group, ethyl group, n-propyl group,isopropyl group, n-butyl group, sec-butyl group, tert-butyl group,pentyl group, hexyl group, heptyl group, octyl group, or the like;alkoxy group such as methoxy group, ethoxy group, n-propoxy group,isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group,pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group or thelike; cycloalkyl group such as cyclopropyl group, cyclobutyl group,cyclopentyl group, cyclohexl group or the like; aryl group such asphenyl group, naphthyl group, anthryl group, biphenyl group or the like,which may be substitute with methyl group, ethyl group or propyl group;and aralkyl group such as benzyl group, phenethyl group or the like,which may be substitute with methyl group, ethyl group or propyl group.

The divalent oxygen atom which may be bonded to an intramolecularsilicon atom by crosslinking or to a silicon atom in the moleculevicinally sited by crosslinking specifically means the oxygen atomsandwiched by two silicon atom when siloxane bond is produced bycrosslinking.

In the general formula (5), the arylene group for Ar₉ and Ar₁ isindependently an arylene group having 6 to 30 carbon atoms, preferablyan arylene group having 6 to 20 carbon atoms, and more preferably aphenylene or naphthylene group which may be substituted with astraight-chain or branched alkyl group having 1 to 6 carbon atoms or acycloalkyl group having 3 to 6 carbon atoms.

Specific examples of the arylene group for Ar₉ and Ar₁₁ independentlyinclude phenylene group, naphthylene group, anthrylene group and thelike, which may be substituted with methyl group, ethyl group or propylgroup.

In addition, Ar₉ and Ar₁₁ in the general formula (5) may be an aromaticamine group represented by the general formula (6). In the generalformula (6), Ar₁₂ and Ar₁₃ are independently an arylene group having 6to 30 carbon atoms, preferably an arylene group having 6 to 20 carbonatoms, and more preferably a phenylene or biphenylene group which may besubstituted with a straight-chain or branched alkyl group having 1 to 6carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms.

Specific examples of Ar₁₂ and Ar₁₃ independently include phenylenegroup, naphthylene group, anthrylene group, biphenylene group and thelike, which may be substituted with methyl group, ethyl group or propylgroup.

In the general formula (6), R₁₂ is a straight-chain or branched alkylgroup having 1 to 2 0 carbon atoms, a cycloalkyl group having 3 to 20carbon atoms, an aryl group having 6 to 30 carbon atoms or an aralkylgroup having 7 to 32 carbon atoms, preferably a straight-chain orbranched alkyl group having 1 to 10 carbon atoms , a cycloalkyl grouphaving 3 to 10 carbon atoms, an aryl group having 6 to 20 carbon atomsor an aralkyl group having 7 to 22 carbon atoms, and more preferably aphenyl or naphthyl group which may be substituted with a straight-chainor branched alkyl group having 1 to 6 carbon atoms or a cycloalkyl grouphaving 3 to 6 carbon atoms.

Specific examples of R₁₂ include phenyl group, naphthyl group, anthrylgroup, biphenyl group and the like, which may be substituted with methylgroup, ethyl group or propyl group.

In the general formula (6), a ring may be formed between Ar₁₂ and Ar₁₃,Ar₁₂ and R₁₂, or Ar₁₃ and R₁₂.

In addition, Ar₉ and Ar₁₁ in the general formula (5) may beindependently an arylene ethenylene group represented by the generalformula (7). In the general formula (7), Ar₁₄ and Ar₁₅ are independentlyan arylene group having 6 to 30 carbon atoms, preferably an arylenegroup having 6 to 20 carbon atoms, and more preferably a phenylene groupwhich may be substituted with a straight-chain or branched alkyl grouphaving 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbonatoms.

Specific examples of Ar₁₄ and Ar₁₅ independently include phenylenegroup, naphthylene group, anthrylene group and the like, which may besubstituted with methyl group, ethyl group or propyl group.

In the general formula (7), R₁₃ and R₁₄ are independently hydrogen atom,a straight-chain or branched alkyl group having 1 to 20 carbon atoms, acycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to30 carbon atoms or an aralkyl group having 7 to 32 carbon atoms,preferably hydrogen atom, a straight-chain or branched alkyl grouphaving 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbonatoms, an aryl group having 6 to 20 carbon atoms or an aralkyl grouphaving 7 to 22 carbon atoms, and more preferably hydrogen atom, astraight-chain or branched alkyl group having 1 to 6 carbon atoms, or aphenyl group which may be substituted with a straight-chain or branchedalkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to6 carbon atoms.

Specific examples of R₁₃ and R₁₄ independently include hydrogen atom,methyl group, ethyl group, propyl group, or phenyl group which may besubstituted with methyl group, ethyl group or propyl group.

In the general formula (5), the aryl group for Ar₁₀ is an aryl grouphaving 6 to 30 carbon atoms, preferably an aryl group having 6 to 20carbon atoms, and more preferably a phenyl or naphthyl group which maybe substituted with a straight-chain or branched alkyl group having 1 to6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms.

Specific examples of the aryl group for Ar₁₀ include phenyl group,naphthyl group, anthryl group and the like, which may be substitutedwith methyl group, ethyl group or propyl group.

In addition, Ar₁₀ in the general formula (5) may be an aromatic aminegroup represented by the general formula (8). In the general formula(8), Ar₁₆ is an arylene group having 6 to 30 carbon atoms, preferably anarylene group having 6 to 20 carbon atoms, and more preferably aphenylene or biphenylene group which may be substituted with astraight-chain or branched alkyl group having 1 to 6 carbon atoms or acycloalkyl group having 3 to 6 carbon atoms.

Specific examples of Ar₁₆ include phenylene group, naphthylene group,anthrylene group, biphenylene group and the like, which may besubstituted with methyl group, ethyl group or propyl group.

In the general formula (8), R₁₅ and R₁₆ are independently astraight-chain or branched alkyl group having 1 to 20 carbon atoms, acycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to30 carbon atoms or an aralkyl group having 7 to 32 carbon atoms,preferably a straight-chain or branched alkyl group having 1 to 10carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an arylgroup having 6 to 20 carbon atoms or an aralkyl group having 7 to 22carbon atoms, and more preferably a phenyl or naphthyl group which maybe substituted with a straight-chain or branched alkyl group having 1 to6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms.

Specific examples of R₁₅ and R₁₆ independently include phenyl group,naphthyl group, anthryl group, biphenyl group and the like, which may besubstituted with methyl group, ethyl group or propyl group.

In the general formula (8), a ring may be formed between Ar₁₆ and R₁₅,Ar₁₆ and R₁₆, or R₁₅ and R₁₆.

In addition, Ar₁₀ in the general formula (5) may be an aryleneethenylene group represented by the general formula (9). Ar₁₇ in thegeneral formula (9) is an arylene group having 6 to 30 carbon atoms,preferably an arylene group having 6 to 20 carbon atoms, and morepreferably a phenylene group which may be substituted with astraight-chain or branched alkyl group having 1 to 6 carbon atoms or acycloalkyl group having 3 to 6 carbon atoms.

Specific examples of Ar₁₇ include phenylene group, naphthylene group,anthrylene group and the like, which may be substituted with methylgroup, ethyl group or propyl group.

In the general formula (9), Ar₁₈ is an aryl group having 6 to 30 carbonatoms, preferably an aryl group having 6 to 20 carbon atoms, and morepreferably a phenyl group which may be substituted with a straight-chainor branched alkyl group having 1 to 6 carbon atoms or a cycloalkyl grouphaving 3 to 6 carbon atoms.

Specific examples of Ar₁₈ include phenyl group, naphthyl group, anthrylgroup and the like, which may be substituted with methyl group, ethylgroup or propyl group.

In the general formula (9), R₁₇ and R₁₈ are independently hydrogen atom,a straight-chain or branched alkyl group having 1 to 20 carbon atoms, acycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to30 carbon atoms or an aralkyl group having 7 to 32 carbon atoms,preferably hydrogen atom, a straight-chain or branched alkyl grouphaving 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbonatoms, an aryl group having 6 to 20 carbon atoms or an aralkyl grouphaving 7 to 22 carbon atoms, and more preferably hydrogen atom, astraight-chain or branched alkyl group having 1 to 6 carbon atoms, or aphenyl group which may be substituted with a straight-chain or branchedalkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to6 carbon atoms.

Specific examples of R₁₇ and R₁₈ independently include hydrogen atom,methyl group, ethyl group, propyl group, or phenyl group which may besubstituted with methyl group, ethyl group or propyl group.

In the general formula (5), a ring may be formed between Ar₉ and Ar₁₀,Ar₉ and Ar₁₁, or Ar₁₀ and Ar₁₁.

In the general formula (10), R₁₉ and R₂₀ are independently hydroxygroup, a straight-chain or branched alkyl or alkoxy group having 1 to 20carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an arylgroup having 6 to 30 carbon atoms or an aralkyl group having 7 to 32carbon atoms, or divalent oxygen atom which may be bonded to anintramolecular silicon atom by crosslinking or to a silicon atom in themolecule vicinally sited by crosslinking, preferably, hydroxy group, astraight-chain or branched alkyl or alkoxy group having 1 to 10 carbonatoms, a cycloalkyl group having 3 to 10 carbon atoms or divalent oxygenatom which may be bonded to an intramolecular silicon atom bycrosslinking or to a silicon atom in the molecule vicinally sited bycrosslinking, and more preferably, hydroxy group, a straight-chain orbranched alkyl or alkoxy group having 1 to 6 carbon atoms or divalentoxygen atom which may be bonded to an intramolecular silicon atom bycrosslinking or to a silicon atom in the molecule vicinally sited bycrosslinking.

Specific examples of R₁₉ and R₂₀ independently include hydroxy group;alkyl group such as methyl group, ethyl group, n-propyl group, isopropylgroup, n-butyl group, sec-butyl group, tert-butyl group, pentyl group,hexyl group, heptyl group, octyl group, or the like; alkoxy group suchas methoxy group, ethoxy group, n-propoxy group, isopropoxy group,n-butoxy group, sec-butoxy group, tert-butoxy group, pentyloxy group,hexyloxy group, heptyloxy group, octyloxy group or the like; cycloalkylgroup such as cycloheptyl group, cyclobutyl group, cyclopentyl group,cyclohexl group or the like; aryl group such as phenyl group, naphthylgroup, anthryl group, biphenyl group or the like, which may besubstitute with methyl group, ethyl group or propyl group; and aralkylgroup such as benzyl group, phenethyl group or the like, which may besubstitute with methyl group, ethyl group or propyl group.

In the general formula (10), R₂₁ is a hydrogen atom or a grouprepresented by the general formula (11), wherein R₂₂, R₂₃ and R₂₄independently represent hydroxy group, a straight-chain or branchedalkyl or alkoxy group having 1 to 20 carbon atoms, a cycloalkyl grouphaving 3 to 20 carbon atoms, an aryl group having 6 to 30 carbon atomsor an aralkyl group having 7 to 32 carbon atoms, preferably hydroxygroup, or a straight-chain or branched alkyl or alkoxy group having 1 to10 carbon atoms, and more preferably hydroxy group or a straight-chainor branched alkyl or alkoxy group having 1 to 6 carbon atoms.

Specific examples of R₂₂, R₂₃ and R₂₄ independently include hydroxygroup; alkyl group such as methyl group, ethyl group, n-propyl group,iso-propyl group, n-butyl group, sec-butyl group, tert-butyl group,pentyl group, hexyl group, heptyl group, octyl group, or the like;alkoxy group such as methoxy group, ethoxy group, n-propoxy group,isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group,pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group or thelike; cycloalkyl group such as cyclopropyl group, cyclobutyl group,cyclopentyl group, cyclohexyl group or the like; aryl group such asphenyl group, naphthyl group, anthryl group, biphenyl group or the like,which may be substituted with methyl group, ethyl group, propyl group.;and aralkyl group such as benzyl group, phenethyl group and the like,which may be substituted with methyl group, ethyl group, propyl group.

In the general formula (10), the arylene group for Ar₁₉ or Ar₂₁ isindependently an arylene group having 6 to 30 carbon atoms, preferablyan arylene group having 6 to 20 carbon atoms, and more preferably aphenylene or naphthylene group which may be substituted with astraight-chain or branched alkyl group having 1 to 6 carbon atoms or acycloalkyl group having 3 to 6 carbon atoms.

Specific examples of the arylene group for Ar₁₉ and Ar₂₁ includephenylene group, naphthylene group, anthrylene group and the like, whichmay be substituted with methyl group, ethyl group or propyl group.

In addition, Ar₁₉ and Ar₂₁ in the general formula (10) may beindependently an aromatic amine group represented by the general formula(6) or an arylene ethenylene group represented by the general formula(7).

Examples of aryl group for Ar₂₀ in the general formula (10) include anaryl group having 6 to 30 carbon atoms, preferably a phenyl group,naphthyl or anthrylene group which may be substituted with astraight-chain or branched alkyl group having 1 to 6 carbon atoms or acycloalkyl group having 3 to 6 carbon atoms.

Specific examples of aryl group for Ar₂₀ include phenyl group, naphthylgroup, anthryl group and the like, which may be substituted with methylgroup, ethyl group or propyl group.

In the general formula (10), Ar₂₀ may be an aromatic amine grouprepresented by the general formula (8), or an arylene ethenylene grouprepresented by the general formula (9).

In the general formula (10), a ring may be formed between Ar₁₉ and Ar₂₀,Ar₁₉ and Ar₂₁, or Ar₂₀ and Ar₂₁.

In the general formula (12), R₂₅, R₂₆ and R₂₇ independently represent astraight-chain or branched alkyl or alkoxy group having 1 to 20 carbonatoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl grouphaving 6 to 30 carbon atoms or an aralkyl group having 7 to 32 carbonatoms, an arylene ethenylene group represented by the general formula(9), an aromatic amine group represented by the general formula (13),preferably a straight-chain or branched alkyl or alkoxy group having 1to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, anarylene ethenylene group represented by the general formula (9), or anaromatic amine group represented by the general formula (13), morepreferably a straight-chain or branched alkyl or alkoxy group having 1to 6 carbon atoms, an arylene ethenylene group represented by thegeneral formula (9), or an aromatic amine group represented by thegeneral formula (13).

Specific examples of R₂₅, R₂₆ and R₂₇ include independently an alkylgroup such as methyl group, ethyl group, n-propyl group, isopropylgroup, n-butyl group, sec-butyl group, tert-butyl group, pentyl group,hexyl group, heptyl group, octyl group, or the like; alkoxy group suchas methoxy group, ethoxy group, n-propoxy group, isopropoxy group,n-butoxy group, sec-butoxy group, tert-butoxy group, pentyloxy group,hexyloxy group, heptyloxy group, octyloxy group or the like; cycloalkylgroup such as cyclopropyl group, cyclobutyl group, cyclopentyl group,cyclohexl group or the like; aryl group such as phenyl group, naphthylgroup, anthryl group, biphenyl group or the like, which may besubstitute with methyl group, ethyl group or propyl group; and aralkylgroup such as benzyl group, phenethyl group or the like, which may besubstitute with methyl group, ethyl group or propyl group.

In the general formula (13), the arylene group for Ar₂₂ is an arylenegroup having 6 to 30 carbon atoms, preferably an arylene group having 6to 20 carbon atoms, and more preferably a phenylene or naphthylene groupwhich may be substituted with a straight-chain or branched alkyl grouphaving 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbonatoms.

Specific examples of the arylene group for Ar₂₂ include phenylene group,naphthylene group, anthrylene group and the like, which may besubstituted with methyl group, ethyl group or propyl group.

In addition, Ar₂₂ in the general formula (13) may be an aromatic aminegroup represented by the general formula (6) or an arylene ethenylenegroup represented by the general formula (7).

In the general formula (13), the aryl group for Ar₂₃ and Ar₂₄ is an arylgroup having 6 to 30 carbon atoms, preferably an aryl group having 6 to20 carbon atoms, and more preferably a phenyl or biphenyl group whichmay be substituted with a straight-chain or branched alkyl group having1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms.

Specific examples of the aryl group for Ar₂₃ and Ar₂₄ include phenylgroup, naphthyl group, anthryl group and the like, which may besubstituted with methyl group, ethyl group or propyl group.

Ar₂₃ and Ar₂₄ in the general formula (13) are independently an aromaticamine group represented by the general formula (8) or an aryleneethenylene group represented by the general formula (9).

The third hole transporting polymer of the present invention is thesecond hole transporting polymer which contains at least one grouprepresented by the above general formula (12) in an amount of from 10%by mole to 150% by mole based on the total silicon atoms belonging tosaid hole transporting polymer except silicon atoms contained in saidgroup, and the content of the hydroxyl group is less than 10% by mole,preferably less than 5% by mole, more preferably less than 1% by mole,based on the total silicon atoms belonging to said hole transportingpolymer except silicon atoms contained in said group.

The third hole transporting polymer of the present invention has beenimproved in durability.

Examples of the structural unit contained in the second holetransporting polymer or the third hole transporting polymer include thestructural unit represented following formula (s1) and (s2).

In the formula, A represents an aromatic amine group in the repeatingstructural unit represented by the general formula (5). B represents anyone of R₈ to R₁₁ in the general formula (5), or the group represented bythe general formula (12).

In the formula, A′ represents an aromatic amine group in the repeatingstructural unit represented by the general formula (10). B′ representsR₁₉ or R₂₀ in the general formula (10) or the group represented by thegeneral formula (12).

The method of producing the first hole transporting polymer of thepresent invention is characterized by hydrolyzing and condensing atleast one silane compound represented by the above general formula (14),and specific examples thereof include method of hydrolyzing andcondensing in the presence or absence of a solvent under an acidic orbasic condition.

A mixture obtained by mixing a silane compound represented by the abovegeneral formula (14) with one or more of a silane compound representedby the following general formula (23) may be hydrolyzed and condensed.

wherein X represents a halogen atom or an alkoxy group having 1 to 6carbon atoms; and R″ represents an alkyl or aryl group having 1 to 12carbon atoms, which may be the same or different.

As the hydrolysis condition, a basic condition is preferred. The baseused to give the basic condition is not specifically limited, andinorganic and organic bases can be used. Among them, an organic base isparticularly preferred. The solvent may be any one which can dissolvethe above silane compounds, and is preferably an organic solvent havinghigh polarity, such as ether solvent, amine solvent or the like. A mixedsolvent of two or more kinds can also be used. The reaction temperatureis usually in the range of from 0 to 150° C., preferably from 40 to 100°C. The reaction time, depending on a silane compound which is hydrolyzedand condensed, is normally from 30 minutes to 100 hours.

In the general formula (14), X is a halogen atom or a straight-chain orbranched alkoxy group having 1 to 20 carbon atoms, preferably a halogenatom or a straight-chain or branched alkoxy group having 1 to 10 carbonatoms, and more preferably a halogen atom or a straight-chain orbranched alkoxy group having 1 to 3 carbon atoms.

Specific examples of X include halogen atom such as iodine, bromine,chlorine, fluorine or the like; and alkoxy group such as methoxy group,ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group,sec-butoxy group, tert-butoxy group, pentyloxy group, hexyloxy group,heptyloxy group, octyloxy group or the like.

Preferable group for R₁, Ar₁, Ar₂ and Ar₃ in the general formula (14)and specific examples thereof are the same as those for R₁, Ar₁, Ar₂ andAr₃ in the general formula (1), and a ring may be formed between Ar₁ andAr₂, Ar₁ and Ar₃, or Ar₂ and Ar₃.

The method of synthesizing the silane compound represented by the abovegeneral formula (14) is not specifically limited, and specific examplesthereof include method of obtaining the silane compound by themethasesis reaction between an alkylhalosilane, alkylalkoxysilane oralkylhaloalkoxysilane compound, and a Grignard reagent or a lithiumreagent of an organic compound.

The method of producing the second hole transporting polymer of thepresent invention is characterized by hydrolyzing and condensing atleast one silane compound represented by the above general formula (15),or a mixture of at least one silane compound represented by the abovegeneral formula (15) and at least one silane compound represented by theabove general formula (16), and specific examples thereof include methodof hydrolyzing and condensing in the presence or absence of a solventunder an acidic or basic condition.

A silane compound represented by the general formula (15) or a mixtureof a silane compound represented by the general formula (15) and asilane compound represented by the above general formula (16) may behydrolyzed and condensed in the presence of a silane compound having analkoxy group or a halogen atom, other than the above silane compound.

As the hydrolysis condition, a basic condition is preferred. The baseused to give the basic condition is not specifically limited, andinorganic and organic bases can be used. Among them, an organic base isparticularly preferred. Examples of an organic base include diethylamine, triethyl amine, butylamine, dibutylamine, tributylamine andpyridine. The solvent may be any one which can dissolve the above silanecompounds, and is preferably an organic solvent having high polarity,such as ether solvent, amine solvent or the like. A mixed solvent of twoor more can also be used. The reaction temperature is usually in therange of from 0 to 150° C., preferably from 40 to 100° C. The reactiontime, depending on a silane compound which is hydrolyzed and condensed,is usually from 30 minutes to 100 hours.

In the general formula (15), R₃₀, R₃₁, R₃₂ and R₃₃ are independently ahalogen atom, a straight-chain or branched alkyl group or alkoxy grouphaving 1-20 carbon atoms, a cycloalkyl group having 3-20 carbon atoms,an aryl group having 6-30 carbon atoms, or an aralkyl group having 7-32carbon atoms, preferably a halogen atom, a straight-chain or branchedalkyl group or alkoxy group having 1-10 carbon atoms or a cycloalkylgroup having 3-10 carbon atoms, more preferably a halogen atom, astraight-chain or branched alkyl group or alkoxy group having 1-6 carbonatoms.

Specific examples of R₃₀, R₃₁, R₃₂ and R₃₃ independently include: ahalogen atom such as iodine, bromine, chlorine and fluorine; an alkylgroup such as methyl group, ethyl group, n-propyl group, isopropylgroup, n-butyl group, sec-butyl group, tert-butyl group, pentyl group,hexyl group, heptyl group, octyl group and the like; an alkoxy groupsuch as methoxy group, ethoxy group, n-propoxy group, isopropoxy group,n-butoxy group, sec-butoxy group, tert-butoxy group, pentyloxy group,hexyloxy group, heptyloxy group, octyloxy group and the like; acycloalkyl group such as cyclopropyl group, cyclobutyl group,cyclopentyl group, cyclohexyl group; an aryl group such as phenyl group,naphtyl group, anthryl group, biphenyl group which may be substitutedwith methyl group, ethyl group and propyl group; an aralkyl group suchas benzyl group, phenetyl group and the like, which may be substitutedwith methyl group, ethyl group and propyl group.

In the general formula (15), R₂₈ and R₂₉ independently are a halogenatom or a straight-chain or branched alkoxy group having 1-20 carbonatoms, preferably a halogen atom, or a straight-chain or branched alkoxygroup having 1-10 carbon atoms, more preferably a halogen atom, or astraight-chain or branched alkoxy group having 1-3 carbon atoms.

Specific examples of R₂₈ and R₂₉ independently include: a halogen atomsuch as iodine, bromine, chlorine and fluorine; an alkoxy group such asmethoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxygroup, sec-butoxy group, tert-butoxy group, pentyloxy group, hexyloxygroup, heptyloxy group, octyloxy group and the like.

Preferable group for Ar₂₅ and Ar₂₇ in the general formula (15) andspecific examples thereof are the same as those of Ar₉ in the generalformula (5) or as those of Ar₁₉ in the general formula (10).

Preferable group for Ar₂₅ and Ar₂₇ in the general formula (15) andspecific examples thereof are the same as those of Ar₁₀ in the generalformula (5). A ring may be formed between Ar₂₅ and Ar₂₆, between Ar₂₅and Ar₂₇, or between Ar₂₆ and Ar₂₇.

In the general formula (16), R₃₅ and R₃₆ independently are a halogenatom, a straight-chain or branched alkyl group or alkoxy group having1-20 carbon atoms, a cycloalkyl group having 3-20 carbon atoms, an arylgroup having 6-30 carbon atoms, or an aralkyl group having 7-32 carbonatoms, preferably a halogen atom, a straight-chain or branched alkylgroup or alkoxy group having 1-10 carbon atoms, or a cycloalkyl grouphaving 3-10 carbon atoms, more preferably a halogen atom, astraight-chain or branched alkyl group or alkoxy group having 1-6 carbonatoms.

Specific example of R₃₅ and R₃₆ independently include: a halogen atomsuch as iodine, bromine, chlorine, fluorine; an alkyl group such asmethyl group, ethyl group, n-propyl group, isopropyl group, n-butylgroup, sec-butyl group, tert-butyl group, a pentyl group, a hexyl group,a heptyl group, an octyl group, and the like; an alkoxy group such asmethoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxygroup, sec-butoxy group, tert-butoxy group, pentyloxy group, hexyloxygroup, heptyloxy group, octyloxy group, and the like; a cycloalkyl groupsuch as cyclopropyl group, cyclobutyl group, cyclopentyl group,cyclohexyl group, and the like; an aryl group such as phenyl group,naphtyl group, anthryl group, biphenyl group, and the like, which may besubstituted with methyl group, ethyl group, and propyl group; and anaralkyl group such as benzyl group, phenetyl group, and the like, whichmay be substituted with methyl group, ethyl group, and propyl group.

In the general formula (16), R₃₄ is a halogen atom, or a straight-chainor branched alkoxy group having 1-20 carbon atoms, preferably a halogenatom or a straight-chain or branched alkoxy group having 1-10 carbonatoms, and more preferably a halogen atom, or a straight-chain orbranched alkoxy group having 1-3 carbon atoms.

Specific examples of R₃₄ include: a halogen atom such as iodine,bromine, chlorine, and fluorine; an alkoxy group such as methoxy group,ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group,sec-butoxy group, tert-butoxy group, pentyloxy group, hexyloxy group,heptyloxy group, octyloxy group, and the like.

In the general formula (16), the arylene group for Ar₂₈ is an arylenegroup having 6-30 carbon atoms, preferably an arylene group having 6-20carbon atoms, and more preferably a phenylene group or a naphthylenegroup which may be substituted with a straight-chain or branched alkylgroup having 1-6 carbon atoms or a cycloalkyl group having 3-6 carbonatoms.

Specific examples of the arylene group in Ar₂₈ include a phenylenegroup, a naphthylene group, an anthrylene group, and the like, which maybe substituted with methyl group, ethyl group, and propyl group.

In the general formula (16), Ar₂₈ may be an arylene ethenylene grouprepresented by the general formula (17).

In the general formula (17), Ar₃₁ and Ar₃₂ are independently an arylenegroup having 6-30 carbon atoms, preferably an arylene group having 6-20carbon atoms, and more preferably a phenylene group which may besubstituted with a straight-chain or branched alkyl group having 1-6carbon atoms or a cycloalkyl group having 3-6 carbon atoms.

Specific examples of Ar₃₁ and Ar₃₂ independently include phenylenegroup, naphthylene group, anthrylene group, and the like, which may besubstituted with methyl group, ethyl group, and propyl group.

In the general formula (17), R₃₇ and R₃₈ independently are hydrogenatom, a straight-chain or branched alkyl group having 1-20 carbon atoms,a cycloalkyl group having 3-20 carbon atoms, an aryl group having 6-30carbon atoms, or an aralkyl group having 7-32 carbon atoms, preferablyhydrogen atom, a straight-chain or branched alkyl group having 1-10carbon atoms, a cycloalkyl group having 3-10 carbon atoms, an aryl grouphaving 6-20 carbon atoms, or an aralkyl group having 7-22 carbon atoms,more preferably hydrogen atom, a straight-chain or branched alkyl grouphaving 1-6 carbon atoms, phenyl group which may be substituted with astraight-chain or branched alkyl group having 1-6 carbon atoms, or acycloalkyl group having 3-6 carbon atoms.

Specific examples of R₃₇ and R₃₈ independently include hydrogen atom,methyl group, ethyl group, propyl group, and phenyl group which may besubstituted with methyl group, ethyl group, and propyl group.

In the general formula (16), the aryl group for Ar₂₉ and Ar₃₀independently is an aryl group having 6-30 carbon atoms, preferably anaryl group having 6-20 carbon atoms, more preferably a phenyl group ornaphtyl group which may be substituted with a straight-chain or branchedalkyl group having 1-6 carbon atoms, or a cycloalkyl group having 3-6carbon atoms.

Specific examples of the aryl group in Ar₂₉ and Ar₃₀ includeindependently, a phenyl group, naphtyl group, anthryl group, and thelike, which may be substituted with methyl group, ethyl group, andpropyl group.

Ar₂₉ and Ar₃₀ in the general formula (16) may be an aromatic amine grouprepresented by the general formula (18).

In the general formula (18), Ar₃₃ is an arylene group having 6-30 carbonatoms, preferably an arylene group having 6-20 carbon atoms, morepreferably a phenylene group or a biphenylene group which may besubstituted with a straight-chain or branched alkyl group having 1-6carbon atoms, or a cycloalkyl group having 3-6 carbon atoms.

Specific examples of Ar₃₃ include phenylene group, naphthylene group,anthrylene group, biphenylene group, and the like, which may besubstituted with methyl group, ethyl group, and propyl group.

R₃₉ and R₄₀ in the general formula (18) independently include astraight-chain or branched alkyl group having 1-20 carbon atoms, acycloalkyl group having 3-20 carbon atoms, an aryl group having 6-30carbon atoms, and an aralkyl group having 7-32 carbon atoms, preferablya straight-chain or branched alkyl group having 1-10 carbon atoms, acycloalkyl group having 3-10 carbon atoms, an aryl group having 6-20carbon atoms, and an aralkyl group having 7-22 carbon atoms, and morepreferably a phenyl group or a naphtyl group which may be substitutedwith a straight-chain or branched alkyl group having 1-6 carbon atoms,or a cycloalkyl group having 3-6 carbon atoms.

Specific examples of R₃₉ and R₄₀ independently include phenyl group,naphtyl group, anthryl group, biphenyl group, and the like, which may besubstituted with methyl group, ethyl group, and propyl group.

In the general formula (18), a ring may be formed between Ar₃₃ and R₃₉,between Ar₃₃ and R₄₀, or between R₃₉ and R₄₀.

Ar₂₉ and Ar₃₀ in the general formula (16) may be an arylene ethenylenegroup represented by the general formula (19).

In the general formula (19), Ar₃₄ is an arylene group having 6-30 carbonatoms, preferably an arylene group having 6-20 carbon atoms, morepreferably a phenylene group which may be substituted with astraight-chain or branched alkyl group having 1-6 carbon atoms, or acycloalkyl group having 3-6 carbon atoms.

Specific examples of Ar₃₄ include a phenylene group, a naphthylenegroup, an anthrylene group, and the like, which may be substituted withmethyl group, ethyl group, and propyl group.

In the general formula (19), Ar₃₄ is an aryl group having 6-30 carbonatoms, preferably an aryl group having 6-20 carbon atoms, morepreferably a phenyl group which may be substituted with a straight-chainor branched alkyl group having 1-6 carbon atoms, or a cycloalkyl grouphaving 3-6 carbon atoms.

Specific examples of Ar₃₄ include a phenyl group, a naphtyl group, ananthryl group, and the like, which may be substituted with methyl group,ethyl group, and propyl group.

In the general formula (19), R₄₁ and R₄₂ independently include hydrogenatom, a straight-chain or branched alkyl group having and 1-20 carbonatoms, a cycloalkyl group having 3-20 carbon atoms, an aryl group having6-30 carbon atoms, and an aralkyl group having 7-32 carbon atoms,preferably hydrogen atom, a straight-chain or branched alkyl grouphaving and 1-10 carbon atoms, a cycloalkyl group having 3-10 carbonatoms, an aryl group having 6-20 carbon atoms, and an aralkyl grouphaving 7-22 carbon atoms, more preferably hydrogen atom, astraight-chain or branched alkyl group having 1-6 carbon atoms, a phenylgroup which may be substituted with a straight-chain or branched alkylgroup having 1-6 carbon atoms or a cycloalkyl group having 3-6 carbonatoms.

Specific examples of R₄₁ and R₄₂ independently include hydrogen atom,methyl group, ethyl group, and propyl group, or a phenyl group which maybe substituted with methyl group, ethyl group, and propyl group. In thegeneral formula (16), a ring may be formed between Ar₂₈ and Ar₂₉,between Ar₂₈ and Ar₃₀, or between Ar₂₉ and Ar₃₀.

The method of synthesizing the silane compounds represented by the abovegeneral formula (15) and (16) are not specifically limited, and specificexamples thereof include method of obtaining the silane compound by themethasesis reaction between an alkylhalosilane, alkylalkoxysilane oralkylhaloalkoxysilane compound, and a Grignard reagent or a lithiumreagent of an organic compound.

The method of producing the second or the third hole transportingpolymer of the present invention is characterized by that a silanecompound represented by the general formula (20) is reacted with a holetransporting polymer manufactured by the above method of producing thesecond hole transporting polymer. Specific examples thereof includemethod of hydrolyzing and condensing in the presence or absence of asolvent under an acidic or basic condition.

As the hydrolysis condition, a basic condition is preferred. The baseused to give the basic condition is not specifically limited, andinorganic and organic bases can be used. Among them, an organic base isparticularly preferred. Examples of an organic base include diethylamine, triethyl amine, butylamine, dibutylamine, tributylamine andpyridine. The solvent may be any one which can dissolve the above silanecompounds, and is preferably an organic solvent having high polarity,such as ether solvent, amine solvent or the like. A mixed solvent of twoor more can also be used.

The reaction temperature is usually in the range of 0 to 150° C.,preferably not lower than 20° C. and not higher than 100° C., and morepreferably not lower than 40° C. and not higher than 80° C.

In the general formula (20), X is a halogen atom, hydroxyl group or astraight-chain or branched alkoxy group having 1-20 carbon atoms,preferably, a halogen atom, hydroxyl group and more preferably, ahalogen atom.

Specific examples of X include: a halogen atom such as iodine, bromine,chlorine, and fluorine; an alkoxy group such as methoxy group, ethoxygroup, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxygroup, tert-butoxy group, a pentyloxy group, a hexyloxy group, aheptyloxy group, an octyloxy group, and the like.

Preferable group for R₂₅, R₂₆, and R₂₇ in the general formula (20) andspecific examples thereof include the same as those of R₂₅, R₂₆ and R₂₇in the general formula (12).

The method of synthesizing the silane compound represented by the abovegeneral formula (20) is not specifically limited, and specific examplesthereof include method of obtaining the silane compound by themethasesis reaction between an alkylhalosilane, alkylalkoxysilane oralkylhaloalkoxysilane compound, and a Grignard reagent or a lithiumreagent of an organic compound.

The organic EL device of the present invention will be describedhereinafter.

The organic electroluminescence device of the present invention ischaracterized by [7] an organic electroluminescence device comprising apair of electrodes of an anode and a cathode, at least one of which istransparent or semitransparent, and at least one layer of an organicmaterial formed between the electrodes, wherein the organic materiallayer contains the first hole transporting polymer [1], the second holetransporting polymer [2] or the third hole transporting polymer [3].

The organic electroluminescence device of the present invention ischaracterized by [8] an organic electroluminescence device comprising apair of electrodes of an anode and a cathode, at least one of which istransparent or semitransparent, and a light emitting layer formedbetween the electrodes, wherein the light emitting layer contains thefirst hole transporting polymer [1], the second hole transportingpolymer [2], or the third hole transporting polymer [3].

The organic electroluminescence device of the present invention ischaracterized by [9] an organic electroluminescence device comprising apair of electrodes of an anode and a cathode, at least one of which istransparent or semitransparent, and a light emitting layer formedbetween the electrodes, wherein a hole transporting layer containing thefirst hole transporting polymer [1], the second hole transportingpolymer [2], or the third hole transporting polymer [3] is providedadjacent to the light emitting layer between the anode and the lightemitting layer.

The organic electroluminescence device of the present invention ischaracterized by [10] the organic electroluminescence device describedin the item [8] or [9], wherein an electron transporting layercontaining an electron transporting material is provided adjacent thelight emitting layer between the cathode and the light emitting layer.

The organic electroluminescence device of the present invention ischaracterized by [11] the organic electroluminescence device describedin any one of the organic EL device, wherein the light emitting layercontains a light emitting polymer, which contains a repeating structuralunit represented by the following general formula (24) in the proportionof 50% by mol based on the total repeating structural units and has apolystyrene-reduced number-average molecular weight of 10³ to 10⁷.

—Ar—CR═CR′  (24)

wherein Ar represents an arylene group or a heterocylic compound grouphaving 4 to 20 carbon atoms which take part in a conjugated bond; and Rand R′ independently represent a group selected from the groupconsisting of hydrogen atom, alkyl group having 1 to 20 carbon atoms,aryl group having 6 to 20 carbon atoms, heterocyclic compound having 4to 20 carbon atoms and cyano group.

The structure of the organic EL device of the present invention is notspecifically limited, and may be any organic EL device having at leastone organic layer between a pair of electrodes of an anode and acathode, at least one of which is transparent or semitransparent,wherein the organic layer contains the above described hole transportingpolymer. Preferred examples of the structure of the organic EL device ofthe present invention include those wherein a light emitting layercontains the hole transporting polymer, those obtained by layering alight emitting layer on a hole transporting layer containing the holetransporting polymer and providing a pair of electrodes on both surfacesand those obtained by layering an electron transporting layer containingan electron transporting material between a light emitting layer and acathode. Single or multi-layer of the light emitting layer and chargetransporting layer independently may be used.

The following charge transporting material, i.e. electron transportingmaterial or hole transporting material may be contained in the holetransporting layer unless th e operation of the hole transportingpolymer is inhibited. When the other hole transporting material is mixedwith the hole transporting polymer, the amount is not more than 100% byweight, preferably not more than 40% by weight, and most preferably notmore than 20% by weight, based on the hole transporting polymer. Whenthe electron transporting material is mixed, the mixing ratio may beappropriately selected considering the luminous efficacy.

The above charge transporting material, which is used alone or incombination thereof in the organic EL device of the present invention,is not specifically limited, and known materials can be used. Examplesof the hole transporting material include pyrazoline derivatives,arylamine derivatives, stilbene derivatives, triphenyldiaminederivatives and the like; and examples of the electron transportingmaterial include oxadiazole derivatives, anthraquinodimethane and itsderivatives, benzoquinone and its derivatives, naphthoquinone and itsderivatives, anthraquinone and its derivatives,tetracyanoanthraquinondimethane and its derivatives, fluorenonederivatives, diphenyldicyanoethylene an d its derivatives,diphenoquinone derivatives, metal complex of 8-hydroxyquinoline and itsderivatives and the like.

Specific examples thereof include those described in JP-A-63-70257,JP-A-63-175860, JP-A-2-135359, JP-A-2-135361, JP-A-2-209988,JP-A-3-37992 and JP-A-3-152184. Among them, the hole transportingmaterial preferably includes triphenyldiamine derivatives and theelectron transporting material preferably includes oxadiazolederivatives, benzoquinone and its derivatives, anthraquinone and itsderivatives and metal complex of 8-hydroxyquinoline and its derivatives.More preferably, the hole transporting material includes4,4′-bis(N(3-methylphenyl)-N-phenylamino)biphenyl and the electrontransporting material includes2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole, benzoquinone,anthraquinone and tris(8-quinolinol)aluminum.

Among them, the compound of the electron transporting material and/orthe compound of the hole transporting material may be used. Theseelectron transporting materials and hole transporting materials may beused alone or in combination thereof.

When the hole transporting layer is provided adjacent to the lightemitting layer and the electron transporting layer is further providedadjacent to the light emitting layer between the light emitting layerand cathode, the electron transporting layer may be formed by using theabove electron transporting material. When the second hole transportinglayer is provided between the hole transporting layer and anode, thesecond hole transporting layer may be formed by using the above holetransporting material.

When the above described charge transporting material and light emittingmaterial are used in combination, the amount of the charge transportingmaterial used varies depending on the kind of the compound to be used.Therefore, the amount may be appropriately decided unless sufficientfilm forming property and light emitting characteristics are inhibited.The amount of the charge transporting material is normally from 1 to 40% by weight, and preferably from 2 to 30% by weight, based on the lightemitting material.

The known light emitting material, which can be used in the lightemitting layer of the organic EL device of the present invention, is notspecifically limited. As the low molecular weight compound, for example,there can be used naphthalene derivatives, anthracene and itsderivatives, perylene and its derivatives, polymethine dyes, xanthenedyes, coumarin dyes and cyanine dyes; and metal complex of8-hydroquinoline and its derivatives, aromatic amine,tetraphenylcyclopentadiene and its derivatives, and tetraphenylbutadieneand its derivatives. Specific examples thereof include known lightemitting materials such as those described in JP-A-57-51781 andJP-A-59-194393.

As the polymeric compound, for example, there can be used conjugatedlight emitting polymers such as poly(p-phenylene) and its derivatives,poly(p-phenylenevinylene) and its derivatives, polyfluorene and itsderivatives, polyquinoline and its derivatives, polyquinoxaline and itsderivatives and the like. Specific examples thereof include known lightemitting polymers such as those described in JP-A-5-202355 andJP-A-5-320635, JP-A-7-97569, JP-A-7-147190, JP-A-7-278276 andJP-A-7-300580.

As the light emitting material contained in the light emitting layer ofthe organic EL device of the present invention, the light emittingpolymer is preferred. Examples of the light emitting polymer includelight emitting polymer as polyarylenevinylene and its derivatives, whichcontains the repeating unit represented by the above general formula(24) in the proportion of not less than 50% by mol based on the totalrepeating structural units and has a polystyrene-reduced number-averagemolecular weight of 10³ to 10⁷. Depending on the structure of therepeating unit, the proportion of the repeating unit represented by theabove general formula (24) is preferably not less than 70% by mol basedon the total repeating structural units. The light emitting polymer maycontain a divalent aromatic compound group or its derivatives, adivalent heterocyclic compound or its derivatives, or a group obtainedby using them in combination as the repeating unit represented by theabove general formula (24). The repeating unit represented by the abovegeneral formula (24) may be bonded in a non-conjugated unit having anether group, an ester group, an amide group, an imide group or the like.Alternatively, the non-conjugated portion may be contained in therepeating unit.

When a light emitting material is a light emitting polymer whichcontains the repeating unit of the general formula (24), Ar of thegeneral formula (24) includes arylene or heterocyclic compound grouphaving 4 to 20 carbon atoms which take part in the conjugated bond.

Examples of Ar are described in JP-10-46138, specifically. Among them,phenylene group, substituted phenylene group, biphenylene group,substituted biphenylene group, naphthalenediyl group, substitutednaphthalenediyl group, anthracene-9,10-diyl group, substitutedanthracene-9,10-diyl group, pyridine-2,5-diyl group, thienylene group orsubstituted thienylene group is preferable. More preferable groups arephenylene group, biphenylene group, naphthalenediyl group,pyridine-2,5-diyl and thienylene group.

When R and R′ of the general formula (24) is a group other than hydrogena cyano group, examples of R and R′ include the alkyl group having 1 to20 carbon atoms such as methyl group, ethyl group, propyl group, butylgroup, pentyl group, hexyl group, heptyl group, octyl group, decylgroup, lauryl group and the like, preferably methyl group, ethyl group,pentyl group, hexyl group, heptyl group and octyl group.

Examples of R and R′ include an aryl group such as phenyl group, 4-C₁₋₁₂alkoxyphenyl group (C₁₋₁₂ shows 1 to 12 carbon atoms, the same ruleapplies correspondingly to the following), 4-C₁₋₁₂alkylphenyl group,1-naphthyl group, 2-naphthyl group and the like.

In view of the solvent solubility , Ar of the general formula (24) ispreferably substituted with a group selected from the group consistingof alkyl, alkoxy or alkylthio group having 4 to 20 carbon atoms, aryl oraryloxy group having 6 to 18 carbon atoms, and heterocyclic compoundgroup having 4 to 14 carbon atoms.

Examples of the substituent are as follows. Examples of the alkyl grouphaving 4 to 20 carbon atoms include butyl group, pentyl group, hexylgroup, heptyl group, octyl group, decyl group, lauryl group and thelike, preferably pentyl group, hexyl group, heptyl group and octylgroup.

Examples of the alkoxy group having 4 to 20 carbon atoms include butoxygroup, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group,decyloxy group, lauryloxy group and the like, preferably pentyloxygroup, hexyoxyl group, heptyloxy group and octyloxy group.

Examples of the alkylthio group include butylthio group, pentylthiogroup, hexylthio group, heptylthio group, octylthio group, decylthiogroup, laurylthio group and the like, preferably pentylthio group,hexylthio group, heptylthio group and octylthio group.

Examples of the aryl group include phenyl group, 4-C₁₋₁₂ alkoxyphenylgroup, 4-C₁₋₁₂alkylphenyl group, 1-naphthyl group, 2-naphthyl group andthe like.

Examples of the aryloxy group include phenoxy group. Examples of theheterocyclic compound group include 2-thienyl group, 2-pyrrolyl group,2-furyl group, 2-, 3- or 4-pyridyl group and the like.

The number of these substituents varies depending on the molecularweight of the light emitting polymer and construction of the repeatingunit. In order to obtain a light emitting polymer having highsolubility, the number of these substituents is preferably at least oneper molecular weight of 600.

The method of synthesizing the light emitting polymer is notspecifically limited, and examples thereof include method described inJP-A-5-202355.

The light emitting polymer used in the organic EL device of the presentinvention may be a random block or graft copolymer, or a polymer havingan intermediate construction of them, e.g. a random copolymer havingblock polymer tendency . In order to obtain a light emitting polymerhaving high quantum yield of fluorescence, the random copolymer having ablock polymer tendency, or block or graft copolymer is better than theperfect random copolymer.

Since the organic EL device of the present invention utilizes lightemission from a thin film, a light emitting polymer having luminescenceat the solid state is used.

Examples of the good solvent to the light emitting polymer includechloroform, methylene chloride, dichloroethane, tetrahydrofuran,toluene, xylene and the like. The light emitting polymer can be normallydissolved in these solvents in an amount of not less than 0.1% byweight, although it varies depending on the structure or molecularweight of the light emitting polymer.

The polystyrene-reduced molecular weight of the light emitting polymerused in the organic EL device of the present invention is preferablywithin the range from 10³ to 10⁷, and the preferable polymerizationdegree depends on the repeated structure and it's proportion. In view ofthe film forming property, the total number of the repeated structuresis preferably within the range from 4 to 10000, more preferably from 5to 3000, and particularly from 10 to 200.

When these light emitting polymers are used as the light emittingmaterial of the organic EL device, since the purity exerts an influenceon light emitting characteristics, the light emitting polymer ispreferably purified by reprecipitation, separation by means ofchromatography or the like, after synthesis.

Next, a typical method of fabricating the organic EL device of thepresent invention will be described. As the pair of transparent orsemitransparent electrodes composed of the anode and cat ho de, forexample, tho se obtained by forming a transparent or semitransparentelectrode on a transparent substrate such as glass, transparent plasticor the like can be used.

As the material of the anode, for example, there can be used conductivemetal oxide films, semitransparent metal thin films and t he like.Specifically films of indium-tin oxide (ITO), tin oxide, zinc oxide, Au,Pt, Ag, Cu and the like are used. Examples of the production methodinclude vacuum deposition method, sputtering method, plating method andthe like.

A hole transporting layer containing a hole transporting polymer of thepresent invention as a hole transporting material is formed on theanode. Example of the method of forming the hole transporting layercontaining the hole transporting polymer of the present inventioninclude method of applying a melt, a solution or a mixed solution of ahole transporting material containing the hole transporting polymer,using an coating method such as spin coating method, casting method,dipping method, bar coating method, roll coating method or the like.

A film thickness of the hole transporting layer is preferably within therange from 0.5 nm to 10 μm, and more preferably from 1 nm to 1 μm. Inorder to enhance the luminous efficacy by increasing the currentdensity, the film thickness is preferably within the range from 10 to800 nm.

Then, a light emitting layer containing a light emitting material isformed. Examples of the method of forming the light emitting layerinclude a coating method such as method of vacuum deposition in thepowdered state of these materials, method of applying a melt, a solutionor a mixed solution of these materials by a spin coating method, acasting method, a dipping method, a bar coating method or roll coatingmethod or the like. In case of using the low molecular weight compound,the vacuum deposition method is preferred. In case of using thepolymeric compound, the method of applying a solution or a mixedsolution by a spin coating method, a casting method, a dipping method, abar coating method or roll coating method is preferred.

A film thickness of the light emitting layer is preferably within therange from 0.5 nm to 10 μm, and more preferably from 1 nm to 1 μm. Inorder to enhance the luminous efficacy by increasing the currentdensity, the film thickness is preferably within the range from 10 to500 nm.

When a thin film of the hole transporting layer and/or that of lightemitting layer are formed by the coating method, it is preferable to drywith heating at a temperature within the range from 30 to 300° C., andpreferably from 60 to 200° C., under reduced pressure or an inertatmosphere so as to remove the solvent after formation of the holetransporting layer and/or light emitting layer.

When an electron transporting layer is further layered on the lightemitting layer, it is preferable to form the electron transporting layerafter the light emitting layer was formed by the above-described filmforming method.

The method of forming the film of the electron transporting layer is notspecifically limited, and there can be used vacuum deposition method inthe powder state; coating method such as spin coating method, castingmethod, dipping method, bar coating method, roll coating method, etc.after dissolving in the solution; or coating method such as spin coatingmethod, casting method, dipping method, bar coating method, roll coatingmethod, etc. after mixing a binder resin with an electron transportingmaterial in the solution or molten state.

A binder resin to be mixed is not specifically limited, but those whichdo not inhibit electron transport are preferable. Those whose absorptionto visible light is not strong are preferably used.

Examples thereof include poly(N-vinylcarbazole) and its derivatives,polyaniline and its derivatives, polythiophene and its derivatives,poly(p-phenylenevinylene) and its derivatives,poly(2,5-thienylenevinylene) and its derivatives, polycarbonate,polyacrylate, polymethyl acrylate, polymethyl methacrylate, polystyrene,polyvinyl chloride, polysiloxane and the like. It is preferable to usethe coating method when using the polymeric compound because a film canbe easily formed.

A film thickness of the electron transporting layer must be a thicknessso that no pin hole is formed. When the film thickness is too large, theresistance of the device increase to require high driving voltage,unfavorably. Accordingly, the film thickness of the electrontransporting layer is preferably within the range from 0.5 nm to 10 μm,more preferably from 1 to 1 μm, and particularly from 5 to 200 nm.

Then, an electrode is formed on the light emitting layer or the electrontransporting layer. This electrode serves as an electron injectioncathode. The material is not specifically limited, but a material havingsmall work function is preferable. For example, there can be used Al,In, Mg, Ca, Li, Mg—Ag alloy, In—Ag alloy, Mg—In alloy, Mg—Al alloy,Mg—Li alloy, Al—Li alloy, graphite thin film and the like. As the methodof producing the cathode, there can be used vacuum deposition method,sputtering method and the like.

EXAMPLES

The following Examples further illustrate the present invention indetail but are not to be construed to limit the scope thereof.

In the following Examples, the molecular weight of the polymer, e.g.polystyrene-reduced number-average molecular weight andpolystyrene-reduced weight-average molecular weight , was measured bygel permeation chromatography (Wasters Co., Maxima-820). Structuralanalysis was performed by using nuclear magnetic resonance absorptionspectrum (¹H, ¹³C-NMR manufactured by Bruker Co., Model AC200P), massspectrum (FD-MS, mass analyzer manufactured by JEOL Ltd., ModelJMS-SX102) and infrared absorption spectrum (IR, manufactured by NipponBIORAD Co.).

Reference Example 1

<Synthesis of Ethyl(4-(2′-(4″-(N,N-diphenylamino)phenyl)ethenyl)phenyl)dichlorosilane>

Under a dry argon atmosphere, n-butyllithium/n-hexane was added dropwiseto a dry tetrahydrofuran solution of the above4-(2′-(4″-(N,N-diphenylamino)phenyl)ethenyl)bromobenzene, and4-(2′-(4″-(N,N-diphenylamino)phenyl)ethenyl)phenyllithium was prepared.

Under a dry argon atmosphere, a solution of the above4-(2′-(4″-(N,N-diphenylamino)phenyl)ethenyl)phenyllithium was addeddropwise to a dry tetrahydrofuran solution of distilledethyltrichlorosilane (3.3 g) at −78° C. After stirring at −78° C. forone hour, the temperature was returned to room temperature. After theexcess ethyltrichlorosilane and solvent were distilled off, dry toluenewas added and a lithium salt was removed by using a glass filter under adry argon atmosphere. It was confirmed by nuclear magnetic resonancespectrum (¹H-NMR) of the resulting reaction product and mass spectrum(FD-MS) of a methoxy derivative[ethyl(4-(2′-(4″-(N,N-diphenylamino)phenyl)ethyenyl)phenyl)dimethoxysilane]thatethyl(4-(2′-(4″-(N,N-diphenylamino)phenyl)ethenyl)phenyl)dichlorosilane)is produced.

¹H-NMR: 1.15 [t] (ethyl group), 1.34 [q] (ethyl group), 7.0-7.7 [m](aromatic group); FD-MS: m/Z 465.

Example 1

<Synthesis of Hole Transporting Polymer 1>

To a dry toluene solution ofethyl(4-(2′-(4″-(N,N-diphenylamino)phenyl)ethenyl)phenyl)dichlorosilane,2 ml of triethylamine was added and 3 ml of a mixed solution oftriethylamine and methanol was further added. After the solvent wasdistilled off, the mixture was dissolved in 50 ml of toluene and thesolution was washed with an aqueous solution of 1N potassium hydroxideusing a separatory funnel. Then, the toluene layer was separated and thesolvent was distilled off. The resulting solid was purified byreprecipitation with ethanol/tetrahydrofuran to obtain 2.7 g of a whitesolid. Hereinafter, this white solid is referred to as a “holetransporting polymer 1”.

In infrared absorption spectrum of the resulting hole transportingpolymer 1, broad signals derived from a siloxane bond were observed atabout 1100 cm⁻¹ and 800 cm⁻¹. In nuclear magnetic resonance absorptionspectrum (¹H-NMR), a broad signal of ethyl group bonded to a siliconatom was observed at about 0.7-1.0 ppm and a broad signal of aromaticprotons was observed at about 6.4-7.6 ppm, the ratio of integratedintensities of these signals is about 1:4. Thus, it was confirmed that4-(2′-(4″-(N,N-diphenylamino)phenyl)ethenyl)phenyl group is incorporatedinto the resulting polymer as a part of the repeating unit. Themolecular weight of the hole transporting polymer 1 was measured by gelpermeation chromatography. As a result, the polystyrene-reducedweight-average molecular weight was 1.3×10⁴ and the polystyrene-reducednumber-average molecular weight was 7.1×10³.

Reference Example 2

<Bromination ofN,N-diphenyl-N′,N′-bis(3″-methylphenyl)-1,1′-biphenyl-4,4′-diamine>

N,N-diphenyl-N′,N′-bis(3″-methylphenyl)-1,1′-biphenyl-4,4′-diamine wasbrominated with N-bromosuccinimide in N,N-dimethylformamide. It wasconfirmed by mass spectrum that a dibromo derivative ofN,N-diphenyl-N′,N′-bis(3″-methylphenyl)-1,1′-biphenyl-4,4′-diamine isproduced.

<Synthesis of Silane Compound 1>

In the same manner as that described in Reference Example 1, a dibromoderivatives ofN,N-diphenyl-N′,N′-bis(3″-methylphenyl)-1,1′-biphenyl-4,4′-diamine waslithiated by using a n-butyllithium/n-hexane solution in a drytetrahydrofuran solution at −78° C. under a dry argon atmosphere, andthen reacted with chloroetrithoxysilane. It was confirmed by massspectrum (FD-MS) and nuclear magnetic resonance spectrum (¹H-NMR) of theresulting reaction product that a triethoxysilyl derivative and abis(triethoxysilyl) derivative ofN,N-diphenyl-N′,N′-bis(3″-methylphenyl)-1,1′-biphenyl-4,4′-diamine areproduced. Hereinafter, this derivatives is referred to as a “silanecompound 1”.

¹H-NMR: 1.26 [t] (ethoxy group), 2.26 [s] (methyl group), 2.39 [s](methyl group), 3.88 [q] (ethoxy group), 6.8-7.6 [m] (aromatic group);FD-MS: m/Z 678 (triethoxysilyl derivatives), 840 (bis(triethoxysilyl)derivatives).

Example 2

<Synthesis of Hole Transporting Polymer 2>

To a tetrahydrofuran solution of the silane compound 1 (about 4 g), 200μl of triethylamine and 100 μl of water were added with stirring. Afterthe solvent was distilled off, the mixture was purified byreprecipitation with tetrahydrofuran/2-propanol to obtain 0.90 g of awhite solid. Hereinafter, this white solid is referred to as a “holetransporting polymer 2”.

In infrared absorption spectrum of the resulting hole transportingpolymer 2, broad signals derived from a siloxane bond were observed atabout 1100 cm⁻¹ and 800 cm⁻¹. In nuclear magnetic resonance absorptionspectrum (¹H-NMR), a broad signal of methyl group on phenyl ring wasobserved at about 1.8-2.4 ppm and a broad signal of aromatic protons wasobserved at about 6.2-7.6 ppm. Thus, it was confirmed thatN,N-diphenyl-N′,N′-bis(3″-methylphenyl)-1,1′-biphenyl-4,4′-diamine groupis incorporated into the resulting polymer as a part of the repeatingunit. The molecular weight of the hole transporting polymer 2 wasmeasured by gel permeation chromatography. As a result, thepolystyrene-reduced weight-average molecular weight was 4.8×10⁵ and thepolystyrene-reduced number-average molecular weight was 9.2×10³.

Reference Example 3

<Bromination of N,N,N′,N′-tetraphenyl-1,1′-biphenyl-4,4′-diamine>

In the same manner as that described in Reference Example 2,N,N,N′,N′-tetraphenyl-1,1′-biphenyl-4,4′-diamine was brominated.

<Synthesis of Silane Compound 2>

In the same manner as that described in Reference Example 2, the abovedibromo derivatives was lithiated by using a n-butyllithium/n-hexanesolution in a dry tetrahydrofuran solution at −78° C. under a dry argonatmosphere, and then reacted with chlorotriethoxysilane. Hereinafter,the resultant is referred to as a “silane compound 2”.

Example 3

<Synthesis of Hole Transporting Polymer 3>

To a toluene solution of the silane compound 2 (0.5 g), about 50 μl oftetrahydrofuran and 10 μl of water were added with stirring. After thesolvent was distilled off, the mixture was purified by reprecipitationwith tetrahydrofuran/2-propanol to obtain 0.10 g of a white solid.Hereinafter, this white sold is referred to as a “hole transportingpolymer 3”.

In infrared absorption spectrum of the resulting hole transportingpolymer 3, broad signals derived from a siloxane bond were observed atabout 1100 cm⁻¹ and 800 cm⁻¹. In nuclear magnetic resonance absorptionspectrum (¹H-NMR), a broad signal of aromatic protons was observed atabout 6.4-7.6 ppm. Thus, it was confirmed thatN,N,N′,N′-tetraphenyl-1,1′-biphenyl-4,4′-diamine group is incorporatedinto the resulting polymrer as a part of the repeating unit. Themolecular weight of the hole transporting polymer 3 was measured by gelpermeation chromatography. As a result, the polystyrene-reducedweight-average molecular weight was 2.3×10⁴ and the polystyrene-reducednumber-average molecular weight was 2.8×10³.

Example 4

<Fabrication and Evaluation of Device Using Hole Transporting Polymer 1>

Using a toluene solution of the hole transporting polymer 1 obtained inExample 1, a film was formed in a thickness of 60 nm by spin coating ona glass substrate on which an ITO film was built up in a thickness of200 nm according to a sputtering method. A uniform film was obtained.After the film was dry at 120° C. under reduced pressure for one hour,tris(8-quinolinol)aluminum (Alq₃) was deposited in a thickness of 70 nmat a rate of 0.1 to 0.2 nm/second as a light emitting/electrontransporting layer. Finally, an aluminum-lithium alloy (Al:Li=about200:1 in weight ratio) was deposited thereon in a thickness of 100 nm asa cathode to fabricate an organic EL device. The vacuum degree duringthe deposition was 1×10⁻⁵ Torr or less.

Regarding this device, the luminance reached 1 cd/m² or more at theapplied voltage of 4.0 V and a current having a current density of 8.8mA/cm² flowed at 6.5 V. Thus, emission of uniform green EL light havinga luminance of 230 cd/m²was observed. At this time, the luminousefficacy was 2.60 cd/A. The luminance was nearly proportional to thecurrent density. Emission of EL light from Alq₃ was confirmed by thefact that the EL spectrum nearly agreed with a fluorescent spectrum of athin film of Alq₃.

Example 5

<Fabrication and Evaluation of Device Using Hole Transporting Polymer 3>

In the same manner as that described in Example 4, except for using thehole transporting polymer 3 in place of the hole transporting polymer 1,an organic EL device was fabricated.

Regarding this device, the luminance reached 1 cd/m² or more at theapplied voltage of 5.0 V and a current having a current density of 9.2mA/cm² flowed at 8.5 V. Thus, emission of uniform green EL light havinga luminance of 194 cd/m² was observed. At this time, the luminousefficacy was 2.12 cd/A. The luminance was nearly proportional to thecurrent density. Emission of EL light from Alq₃ was confirmed by thefact that the EL spectrum nearly agreed with a fluorescent spectrum of athin film of Alq₃.

This device was continuously driven in a nitrogen flow at a currentdensity of 25 mA/cm². As a result, a driving voltage was increasedslightly from 7.7 V to 9.2 V after 30 hours.

Reference Example 4

<Synthesis of Light Emitting Polymer 1>

2,5-dioctyloxy-p-xylylene dichoride was reacted with triphenylphosphinein a N,N-dimethylformamide solvent to synthesize a phosphonium salt.47.78 g of the resulting phosphonium salt and 5.5 g ofterephthalaldehyde were dissolved in an ethyl alcohol/chloroform mixedsolvent. An ethyl alcohol/chloroform mixed solution containing 5.4 g oflithium ethoxide was added dropwise to an ethyl alcohol of a phosphoniumsalt and dialdehyde, followed by polymerization. To the resultingreaction solution, a chloroform solution of 1-pyrenecarboxaldehyde wasadded and an ethyl alcohol solution containing lithium ethoxide wasfurther added dropwise, and then the mixed solution was polymerized atroom temperature for 3 hours. After the reaction solution was allowed tostand at room temperature overnight, the precipitate was collected byfiltration and the precipitate was washed with ethyl alcohol anddissolved in chloroform. Ethanol was added to the solution to form aprecipitate again. The precipitate was dry to obtain 8.0 parts by weightof a polymer.

This polymer is referred to as a “light emitting polymer 1”. A repeatingunit of the light emitting polymer 1 calculated from a charging ratio ofmonomers, and its molar ratio are shown below. It was confirmed by¹H-NMR that the polymer has a pyrenyl group at the molecular terminal.

wherein a molar ratio of two repeating units is 50:50 and two repeatingunits are bonded each other.

The polystyrene-reduced number-average molecular weight of the lightemitting polymer 1 was 4.0×10³. The structure of the light emittingpolymer 1 was confirmed by infrared absorption spectrum and NMR.

Example 6

<Fabrication and Evaluation of Device Using Hole Transporting Polymer 1>

Using a toluene solution of the hole transporting polymer 1 obtained inExample 1, a film was formed in a thickness of 55 nm by spin coating ona glass substrate on which an ITO film was built up in a thickness of200 nm according to a sputtering method. A uniform film was obtained. Onthis film, a 2% decalin solution of the light emitting polymer 1obtained in Reference Example 4 was spin-coated. Then,tris(8-quinolinol)aluminum (Alq₃) was deposited in a thickness of 50 nmat a rate of 0.1 to 0.2 nm/second as an electron transporting layer.Finally, an aluminum-lithium alloy (Al:Li=about 200:1 in weight ratio)was deposited thereon in a thickness of 40 nm as a cathode to fabricatean organic EL device. The vacuum degree during the deposition was 1×10⁻⁵Torr or less.

Regarding this device, the luminance reached 1 cd/m² or more at theapplied voltage of 5.5 V and emission of uniform yellowish green ELlight having a luminance of 100 cd/m² at 8.3 V was observed. At thistime, the luminous efficacy was 3.0 cd/A. The luminance was nearlyproportional to the current density. Emission of EL light from lightemitting polymer 1 was confirmed by the fact that the EL spectrum nearlyagreed with a fluorescent spectrum of a thin film of light emittingpolymer 1.

This device was continuously driven in a nitrogen flow at a currentdensity of 25 mA/cm². As a result, the luminance was 549 cd/m²at first,but the luminance was about 210 cd/m² even after 50 hours. The drivingvoltage was increased from 11 V to 18 V during this time.

Example 7

<Fabrication and Evaluation of Device Using Hole Transporting Polymer 2>

In the same manner as that described in Example 6, except f or using thehole transporting polymer 2 in place of the hole transporting polymer 1,a device was fabricated. At this time, the film thickness of the holetransporting polymer 2 was about 25 nm.

Regarding this device, the luminance reached 1 cd/m² or more at theapplied voltage of 4.25 V and emission of uniform yellowish green ELlight having a luminance of 100 cd/m² at 6.3 V was observed. At thistime, the luminous efficacy was 3.0 cd/A. The luminance was nearlyproportional to the current density. Emission of EL light from lightemitting polymer 1 was confirmed by the fact that the EL spectrum nearlyagreed with a fluorescent spectrum of a thin film of light emittingpolymer 1.

This device was continuously driven in a nitrogen flow at a currentdensity of 25 mA/cm². As a result, the luminance was 625 cd/M² at first,but the luminance was about 503 cd/m² even after 50 hours. The drivingvoltage was increased slightly from 7.8 V to 9.7 V during this time.

Comparative Example 1

<Fabrication and Evaluation of Device>

In the same manner as that described in Example 5, except for forming afilm using a methylene chloride solution of polyvinyl carbazole in placeof the hole transporting polymer 3 by a dipping method, an organic ELdevice was fabricated.

Regarding this device, the luminance reached 1 cd/m² or more at theapplied voltage of 4.25 V and a current having a current density of 17.1mA/cm² flowed at 6.5 V. Thus, emission of uniform green EL light havinga luminance of 288.2 cd/m² was observed. At this time, the luminousefficacy was 1.68 cd/A. The luminance was nearly proportional to thecurrent density. Emission of EL light from Alq₃ was confirmed by thefact that the EL spectrum nearly agreed with a fluorescent spectrum of athin film of Alq₃.

This device was continuously driven in a nitrogen flow at a currentdensity of 25 mA/cm². As a result, a driving voltage was increased from5.7 V to 7.8 V after 30 hours.

Comparative Example 2

<Fabrication and Evaluation of Device>

In the same manner as that described in Example 6, except for forming afilm using a methylene chloride solution of polyvinyl carbazole in placeof the hole transporting polymer 1 as the hole transporting polymer by adipping method, an organic EL device was fabricated.

Regarding this device, the luminance reached 1 cd/m² or more at theapplied voltage of 5.0 V and emission of uniform green EL light having aluminance of 100 cd/m² at 7.6 V was observed. At this time, the luminousefficacy was 3.3 cd/A. The luminance was nearly proportional to thecurrent density.

This device was continuously driven in a nitrogen flow at a currentdensity of 25 mA/cm². As a result, the luminance was 670 cd/m² at first,but the luminance was reduced to about 256 cd/m² after 50 hours and thedriving voltage was increased from 11 V to 19.8 V.

Reference Example 5

<Synthesis of Silane Compound 3>

Under a dry argon atmosphere, n-butyllithium/n-hexane (17 ml) was addeddropwise to a dry tetrahydrofuran solution of the dibromo derivative ofN,N′-diphenyl-N,N′-bis(3″-methylphenyl)-1,1′-biphenyl-4,4′-diamine (8.0g) which was prepared as the same manner with Reference Example 2, at−78° C., dilithium-derivative ofN,N′-diphenyl-N,N′-bis(3″-methylphenyl)-1,1′-biphenyl-4,4′-diamine wasprepared.

Under a dry argon atmosphere, a solution of the abovedilithium-derivative ofN,N′-diphenyl-N,N′-bis(3″-methylphenyl)-1,1′-biphenyl-4,4′-diamine wasadded dropwise to a dry tetrahydrofuran solution ofdimethoxymethylchlorosilane (7.0 g) at −78° C. After stirring at −78° C.for one hour, the temperature was returned to room temperature. Afterthe excess dimethoxymethylchlorosilane and the solvent were distilledoff, dry toluene was added and a lithium salt was removed by using aglass filter under a dry argon atmosphere. After the solvent wasdistilled, a viscous solid (7.1 g) was obtained. It was confirmed bynuclear magnetic resonance spectrum (¹H-NMR) of the resulting reactionproduct that dimethoxymethylsilyl derivative andbis(dimethoxymethylsilyl) derivative ofN,N′-diphenyl-N,N′-bis(3″-methylphenyl)-1,1′-biphenyl-4,4′-diamine wereproduced. (Hereinafter, referred to as a “silane compound 3”).

¹H-NMR: 0.40[s] (methyl group bonded to silicon atom), 2.28[s] (methylgroup), 3.60[s] (methoxy group), 6.8-7.6 [m] (aromatic group).

Example 8

<Synthesis of Hole Transporting Polymer 4>

To a dry tetrahydrofuran solution of silane compound 3 (6.5 g), 3.5 mlof triethylamine and 0.65 ml of water were added with stirring andfurther stirring at 60° C. After the solvent was distilled off, theresulting solid was purified by reprecipitation withtetrahydrofuran/2-propanol to obtain 3.17 g of a white solid.Hereinafter, this white solid is referred to as a “hole transportingpolymer 4”.

In nuclear magnetic resonance spectrum (¹H-NMR) of the resulting holetransporting polymer 4, a signal of methyl group bonded to silicon atomat about 0.0-0.7 ppm, a broad signal of methyl group on a phenyl ring atabout 1.8-2.4 ppm, a signal of methoxy group at about 3.4-3.7 ppm, and abroad signal of aromatic protons at about 6.2-7.6 ppm were observed.

In infrared absorption spectrum, broad signals derived from a siloxanebond at about 1100 cm⁻¹ and 800 cm⁻¹ and broad signals derived fromhydroxyl group at about 3300 cm⁻¹ were observed. It was confirmed thatN,N′-diphenyl-N,N′-bis(3″-methylphenyl)-1,1′-biphenyl-4,4′-diamine groupwas incorporated to the obtained polymer as a part of the repeatingunits, and a part of hydroxyl groups resulting by hydrolysis remained asunreact. The molecular weight of the hole transporting polymer 4 wasmeasured by gel permeation chromatography. As a result, thepolystyrene-reduced weight-average molecular weight was 2.2×10⁴ and thepolystyrene-reduced number-average molecular weight was 6.2×10³.

Example 9

<Synthesis of Hole Transporting Polymer 5>

To 15 ml of tetrahydrofuran solution of the hole transporting polymer 4(1.0 g) synthesized as the same manner with Example 8, 3 ml oftriethylamine was added, then 1.7 g of triphenylchlorosilane was added,and stirred at 55° C. Water was added in order to deactivate the excesstriphenylchlorosilane. After the solvent was distilled, it was dissolvedin toluene, and after washed with water using a separatory funnel, thetoluene layer was separated and the solvent was distilled. The resultantsolid was purified by reprecipitation with tetrahydrofuran/2-propanol,and 0.85 g of white solids was obtained. Hereafter, this is referred toas a “hole transporting polymer 5”.

From integrated intensities of the signal in nuclear-magnetic-resonanceabsorption spectrum (¹H-NMR) of the resultant hole transporting polymer5, it confirmed that triphenyl silygroup was incorporated.

In the infrared-absorption spectrum, although strength is weak, a broadsignal derived from the hydroxyl group was observed at about 3300 cm⁻¹.It was confirmed that the hydroxyl group still remained. The molecularweight of hole transporting polymer 5 was measured by gel permeationchromatography, and polystyrene-reduced weight-average molecular weightwas 2.4×10⁴ and the polystyrene-reduced number average molecular weightwas 7.9×10³.

<Synthesis of Hole Transporting Polymer 6>

To 20 ml of tetrahydrofuran solution of the above hole transportingpolymer 5 (0.65 g), 4 ml of triethylamine was added, thentrimethylchlorosilane 0.23 g was added, and stirred at room temperature.After work-up was conducted as the same manner as that of Example 9, theresultant solid was purified by reprecipitation withtetrahydrofuran/ethanol, and 0.62 g of white solids was obtained.Hereafter, this is referred to as a “hole transporting polymer 6”.

In the nuclear-magnetic-resonance absorption spectrum of the resultanthole transporting polymer 6 (¹H-NMR), methyl signal of trimethylsilylGroup is observed at about −0.1-0.1 ppm, and it confirmed that atrimethylsilyl group was incorporated. A signal was not observed atabout 3300 cm⁻¹ in infrared-absorption spectrum, and it was confirmedthat the hydroxyl group does not remained. The molecular weight of holetransporting polymer 6 was measured by gel permeation chromatography,and the polystyrene reduced weight-average molecular weight was 2.5×10⁴and the polystyrene-reduced number average molecular weight was 8.1×10³.

Example 10

<Synthesis of Hole Transporting Polymer 7>

To 20 ml of tetrahydrofuran solution of hole transporting polymer 5(0.65 g) synthesized as the same manner as Example 9, 4 ml oftriethylamine was added, then diphenylmethyl chlorosilane 0.43 g wasadded, and stirred at 55° C. After work-up was conducted as the samemanner as that of Example 9, the resultant solid was purified byreprecipitation with tetrahydrofuran/ethanol, and 0.48 g of white solidswas obtained. Hereafter, this is referred to as “hole transportingpolymer 7”.

In the nuclear-magnetic-resonance absorption spectrum of the resultanthole transporting polymer 7 (¹H-NMR), a signal of the methyl group ofdiphenylmethylsilyl group was observed at about 0.4-0.6 ppm, and it wasconfirmed that a diphenylmethylsilyl group was incorporated. A signalwas not observed at about 3300 cm⁻¹in infrared-absorption spectrum, andit was confirmed that the hydroxyl group does not remained. Themolecular weight of hole transporting polymer 7 was measured by gelpermeation chromatography, and the polystyrene-reduced weight-averagemolecular weight was 2.9×10⁴ and the number-average molecular weight was9.5×10³.

Reference Example 6

<Synthesis of 4-(2′-(1″-pyrenyl)ethenyl)bromobenzene>

4-bromobenzyl bromide (product made from Tokyo Kasei) was reacted withtriphenyl phosphine in dry acetone solvent, and the phosphonium salt wasobtained. To dry ethanol solution of the resultant phosphonium salt 45 gand 1-pyrene carboxy aldehyde (product made from Aldrich Co.) 24.3 g,ethanol solution of lithium ethoxide (obtained by reacting lithium 1.5 gwith dry ethanol 100 ml) was added dropwise, and 4-(2′-(1″-pyrenyl)ethenyl)bromobenzene was prepared. It was purified by silica-gel columnchromatography and 34.9 g of yellow sol id was obtained.

<Synthesis of 4-(2′-(1″-pyrenyl)ethenyl)dimethylchloro silane>

As the same manner with Reference Example 1,4-(2′-(1″-pyrenyl)ethenyl)bromobenzene was lithiated with n-butyllithium/n-hexane solution in dry tetrahydrofuran solution at −78° C.,under dry argon atmosphere, then reacted with dimethyldichlorosilane. Bythe nuclear-magnetic-resonance spectrum of the resultant product(¹H-NMR), it was confirmed that4-(2′-(1″-pyrenyl)ethenyl)dimethylchlorosilane was formed.

Example 11

<Synthesis of Hole Transporting Polymer 8>

To 15 ml of tetrahydrofuran solution of the hole transporting polymer 4(1.0 g) synthesized as the same manner with Example 8, triethylamine 3ml was added, then 4-(2′-(1″-pyrenyl)ethenyl)dimethylchlorosilane 1.7 gwas added, and stirred at room temperature. After work-up as the samemanner as that of Example 9, the resultant solid was purified byreprecipitation with tetrahydrofuran/2-propanol, and 0.98 g of whitesolid was obtained. Hereafter, this is referred to as “hole transportingpolymer 8”.

In the nuclear-magnetic-resonance absorption spectrum of the resultanthole transporting polymer 8 (¹H-NMR), the signal of aromatic protons of4-(2′-(1″-pyrenyl)ethenyl)dimethylsilyl group was observed at about7.6-8.5 ppm, and it was confirmed that4-(2′-(1″-pyrenyl)ethenyl)dimethylsilyl group was incorporated. In theinfrared-absorption spectrum, a signal was not observed at about 3300cm⁻¹, and it was confirmed that hydroxyl group does not remained. Themolecular weight of hole transporting polymer 8 was measured by gelpermeation chromatography, and the polystyrene-reduced weight-averagemolecular weight was 2.8×10⁴ and the polystyrene-reduced number-averagemolecular weight was 7.0×10³.

Reference Example 7

<Synthesis of Light Emitting Polymer 2>

2,5-dioctyloxy-p-xylylene dichloride was reacted with triphenylphosphine in N,N-dimethylformamide solvent, and the phosphonium salt wasprepared. 4.78 g of the resultant phosphonium salt, 4.28 g of thephosphonium salt of 2-methoxy-5-octyloxy-p-xylylene dichloride obtainedsimilarly, terephthalaldehyde 1.01 g and 1-pyrenecarboxyaldehyde 1.15 gwere dissolved in a mixed solvent of ethanol 80 g/chloroform 100 g.

A mixed solution of a 12% methanol solution of lithium methoxide 10ml/ethanol 40 ml, was added dropwise to a mixed solution of ethylalcohol/chloroform of the phosphonium salt and the aldehyde, thenfurther reacted for 4 hours at room temperature. After standing itovernight at room temperature, precipitates were collected and washedwith ethyl alcohol. Then the precipitates were dissolved in toluene, andpurified by reprecipitation twice with adding ethanol. After drying in areduced pressure, 2.0 g of light emitting polymer was obtained.

This is referred to as a “light emitting polymer 2”. The repeating unitand its molar ratio of the light emitting polymer 2 which is calculatedfrom the charged monomer ratio are shown below. It was confirmed thatpyrenyl group is incorporated to the molecular terminal from ¹H-NMR.

The polystyrene-reduced number-average molecular weight of this lightemitting polymer 2 was 2.5×10³. The structure of this light emittingpolymer 2 was confirmed by infrared-absorption spectrum and NMR.

Example 12

<Fabrication and Evaluation of a Device Using Hole Transporting Polymer6>

To a glass substrate on which ITO film was built up in a thickness of200 nm according to the sputtering method, a film was formed in athickness of 60 nm with spin coating with using toluene solution of theresultant hole transporting polymer 6 of Example 9. A uniform film wasobtained.

On this film, a 2% decalin solution of the light emitting polymer 2obtained in Reference Example 7 was spin coated. Subsequently, as anelectron transporting layer, tris(8-quinolinol)aluminium (Alq₃) wasdeposited at a rate of 0.1 nm/s in a thickness of 40 nm. Finally,aluminium lithium alloy (Al:Li=about 200:1 in weight ratio) as a cathodewas deposited on it in a thickness of 40 nm, and an organicelectroluminescence device was fabricated. The vacuum degree during thedeposition was always 1×10⁻⁵ Torrs or less.

In the device, the luminance is 1 cd/m² or more at applied voltage of3.5V, and yellow green uniform EL luminescence of 100 cd/m² at 5.25V wasobserved. The luminous efficacy at this time was 3.09 cd/A. Theluminance was almost proportional to a current density.

Emission of EL light from light emitting polymer 2 was confirmed by thefact that the EL spectrum nearly agreed with a fluorescent spectrum of athin film of light emitting polymer 2.

In continuation driving of this device in nitrogen atmosphere with acurrent density of 25mA/cm², the luminance of early stage is 878 cd/m²,and the luminance after 50 hours was about 513 cd/m². The drivingvoltage went up from 6.8V to 14.5V during this time.

Example 13

<Fabrication and Evaluation of a Device Using Hole Transporting Polymer7>

The device was fabricated as the same manner with Example 12 excepthaving used the toluene solution of the hole transporting polymer 7obtained in Example 10 instead of the toluene solution of the holetransporting polymer 6 of Example 12. The film thickness of the holetransporting polymer 7 was 45 nm. In the device, the luminance is 1cd/m² or more at applied voltage of 3.75V, and yellow green uniform ELluminescence of 100 cd/m² at 5.50V was observed.

The luminous efficacy at this time was 2.06 cd/A. The luminance wasalmost proportional to a current density.

Emission of EL light from light emitting polymer 2 was confirmed by thefact that the EL spectrum nearly agreed with a fluorescent spectrum of athin film of light emitting polymer 2.

In continuation driving of this device in nitrogen atmosphere with acurrent density of 25mA/cm², the luminance of early stage is 602 cd/m²,and the luminance after 50 hours was about 451 cd/m². The drivingvoltage went up from 6.5V to 11.9V during this time.

Example 14

<Fabrication and Evaluation of a Device Using Hole Transporting Polymer8>

The device was fabricated as the same manner with Example 12 excepthaving used the toluene solution of the hole transporting polymer 8instead of the toluene solution of the hole transporting polymer 6 ofExample 12. The film thickness of the hole transporting polymer 8 was 46nm. In the device, the luminance was 1 cd/m² or more at applied voltageof 3.50V, and yellow green uniform EL luminescence of 100 cd/m² at 5.25Vwas observed.

The luminous efficacy at this time was 2.83 cd/A. The luminance wasalmost proportional to a current density.

Emission of EL light from light emitting polymer 2 was confirmed by thefact that the EL spectrum nearly agreed with a fluorescent spectrum of athin film of light emitting polymer.

In continuation driving of this device in nitrogen atmosphere with acurrent density of 25mA/cm², the driving voltage went up from 6.4V to11.3V during this time.

The hole transporting polymer of the present invention has excellenthole transporting property, and is superior in durability andfilm-forming property. The organic EL device using the hole transportingpolymer has excellent light emitting characteristics in comparison withthe conventional art, and its industrial value is great.

What is claimed is:
 1. A hole transporting polymer comprising arepeating structural unit represented by the following general formula(5), and having a polystyrene-reduced number-average molecular weight offrom 10³ to 10⁷:

wherein Ar₉ and Ar₁₁ independently represent an arylene group having 6to 30 carbon atoms, an aromatic amine group represented by the followinggeneral formula (6) or an arylene ethenylene group represented by thefollowing general formula (7); Ar₁₀ represents an aryl group having 6 to30 carbon atoms, an aromatic amine group represented by the followinggeneral formula (8) or an arylene ethenylene group represented by thefollowing general formula (9); a ring may be formed between Ar₉ andAr₁₀, or A₉ and Ar₁₁, or Ar₁₀ and Ar₁₁; and R₈, R₉, R₁₀ and R₁₁independently represent a hydroxy group, an alkyl or alkoxy group having1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, a grouprepresented by the following general formula (10 ) or (12), or adivalent oxygen atom which is bonded to an intramolecular silicon atomby crosslinking or to an intermolecular silicon atom by crosslinking:

wherein Ar₁₂ and Ar₁₃ independently represent an arylene group having 6to 30 carbon atoms; R₁₂ represents an alkyl group having 1 to 20 carbonatoms or an aryl group having 6 to 30 carbon atoms; and a ring may beformed between Ar₁₂ and Ar₁₃, or Ar₁₂ and R₁₂, or Ar₁₃ and R₁₂:

wherein Ar₁₄ and Ar₁₅ independently represent an arylene group having 6to 30 carbon atoms; and R₁₃ and R₁₄ independently represent a hydrogenatom, an alkyl group having 1 to 20 carbon atoms, or an aryl grouphaving 6 to 30 carbon atoms:

wherein Ar₁₆ represents an arylene group having 6 to 30 carbon atoms;R₁₅ and R₁₆ independently represent an alkyl group having 1 to 20 carbonatoms, or an aryl group having 6 to 30 carbon atoms; and a ring may beformed between Ar₁₆ and R₁₅, or Ar₁₆ and R₁₆, or R₁₅ and R₁₆:

wherein Ar₁₇ represents an arylene group having 6 to 30 carbon atoms;R₁₇ and R₁₈ independently represent hydrogen atom, an alkyl group having1 to 20 carbon atoms, or an aryl group having 6 to 30 carbon atoms; andAr₁₈ represents an aryl group having 6 to 30 carbon atoms:

wherein Ar₁₉ and Ar₂₁ independently represent an arylene group having 6to 30 carbon atoms, an aromatic amine group represented by the abovegeneral formula (6) or an arylene ethenylene group represented by theabove general formula (7); Ar₂₀ represents an aryl group having 6 to 30carbon atoms, an aromatic amine group represented by the above generalformula (8) or an arylene ethenylene group represented by the abovegeneral formula (9); and a ring may be formed between Ar₁₉ and Ar₂₀, orAr₁₉ and Ar₂₁, or Ar₂₀ and Ar₂₁; R₁₉ and R₂₀ independently represent ahydroxy group, an alkyl or alkoxy group having 1 to 20 carbon atoms, anaryl group having 6 to 30 carbon atoms, or divalent oxygen atom which isbonded to an intramolecular silicon atom by crosslinking or to anintermolecular silicon atom by crosslinking; R₂₁ represents hydrogenatom or a group represented by the following general formula (11):

wherein R₂₂, R₂₃ and R₂₄ independently represent a hydroxy group, analkyl group or alkoxy group having 1 to 20 carbon atoms, or an arylgroup having 6 to 30 carbon atoms:

wherein R₂₅, R₂₆ and R₂₇, independently represent an alkyl group having1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, or anarylene ethenylene group represented by the above general formula (9) oran aromatic amine group represented by the following general formula(13):

wherein Ar₂₂ represents an arylene group having 6 to 30 carbon atoms, anaromatic amine group represented by the above general formula (6) or anarylene ethenylene group represented by the above general formula (7);Ar₂₃ and Ar₂₄ independently represent an aryl group having 6 to 30carbon atoms, an aromatic amine group represented by the above generalformula (8) or an arylene ethenylene group represented by the abovegeneral formula (9).
 2. The hole transporting polymer according to claim1, wherein the compound group represented by the above general formula(12) in claim 1 is in an amount of from 10% by mole to 150% by molebased on the total silicon atoms belonging to said hole transportingpolymer but exclusive of the silicon atoms in said compound group; andthe hydroxy group bonded to a silicon atom is in an amount of less than10% by mole based on the total silicon atoms belonging to said holetransporting polymer but exclusive of the silicon atoms in said compoundgroup.
 3. The method of producing a hole transporting polymer of claim1, wherein at least one silane compound represented by the followinggeneral formula (15), or a mixture of at least one silane compoundrepresented by the following general formula (15) and at least onesilane compound represented by the following general formula (16) ishydrolyzed and condensed:

wherein R₃₀, R₃₁, R₃₂ and R₃₃ independently represent a halogen atom, analkyl group or alkoxy group having 1 to 20 carbon atoms or an aryl grouphaving 6 to 30 carbon atoms; R₂₈ and R₂₉ independently represent ahydroxy group or an alkoxy group having 1 to 20 carbon atoms; Ar₂₅ andAr₂₇ are the same as Ar₉ and Ar₁₁ as defined in the general formula (5)of claim 1; Ar₂₆ is the same as Ar₁₀ as defined in the general formula(5) of claim 1; and a ring may be formed between Ar₂₅ and Ar₂₆, or Ar₂₅and Ar₂₇, or Ar₂₆ and Ar27:

wherein R₃₅ and R₃₆ independently represent a halogen atom, an alkylgroup or alkoxy group having 1 to 20 carbon atoms or an aryl grouphaving 6 to 30 carbons atoms; R₃₄ represents a halogen atom, an alkoxygroup having 1 to 20 carbon atoms; Ar₂₈ represents an arylene grouphaving 6 to 30 carbon atoms or an arylene ethenylene group representedby the following general formula (17); Ar₂₉ and Ar₃₀ independentlyrepresent an aryl group having 6 to 30 carbon atoms, an aromatic aminegroup represented by the following general (18) or an arylene ethenylenegroup represented by the following general formula (19); and a ring maybe formed between Ar₂₈ and Ar₂₉, or Ar₂₈ and Ar₃₀, or Ar₂₉ and Ar₃₀;

wherein Ar₃₁ and Ar₃₂ independently represent an arylene group having 6to 30 carbon atoms; R₃₇ and R₃₈ independently represent a hydrogen atom,an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to30 carbons atoms:

wherein Ar₃₃ represents an arylene group having 6 to 30 carbon atoms;R₃₉ and R₄₀ independently represent an alkyl group having 1 to 20 carbonatoms or an aryl group having 6 to 30 carbon atoms; and a ring may beformed between Ar₃₃ and R₃₉, or Ar₃₃ and R₄₀, or R₃₉ and R₄₀:

wherein Ar₃₄ represents an arylene group having 6 to 30 carbon atoms;R₄₁, and R₄₂ independently represent a hydrogen atom, an alkyl grouphaving 1 to 20 carbon atoms or an aryl group having 6 to 30 carbonatoms; and Ar₃₅ represents an aryl group having 6 to 30 carbon atoms. 4.The method of producing a hole transporting polymer according to claim3, wherein the hole transporting polymer obtained by claim 3 is furtherreacted with the compound represented by the following general formula(20),

wherein X represents a halogen atom or an alkoxy group having 1 to 20carbon atoms; R₂₅, R₂₆, and R₂₇ independently represent an alkyl grouphaving 1 to 20 carbon atoms or an aryl group having 6 to 30 carbonatoms, an arylene ethenylene group represented by the following formula(9) or an aromatic amine group represented by the following generalformula (13):

wherein Ar₁₇ represents an arylene group having 6 to 30 carbon atoms;R₁₇ and R₁₈ independently represent hydrogen atom, an alkyl group having1 to 20 carbon atoms or an aryl group having 6 to 30 carbon atoms; andAr₁₈ represents an aryl group having 6 to 30 carbon atoms:

wherein Ar₂₂ represents an arylene group having 6 to 30 carbon atoms, anaromatic amine group represented by the following formula (6) or anarylene ethenylene group represented by the following formula (7); Ar₂₃and Ar₂₄ independently represent an aryl group having 6 to 30 carbonatoms, an aromatic amine group represented by the following formula (8)or an arylene ethenylene group represented by the above formula (9),

wherein Ar₁₂ and Ar₁₃ independently represent an arylene group having 6to 30 carbon atoms; R₁₂ represents an alkyl group having 1 to 20 carbonatoms or an aryl group having 6 to 30 carbon atoms: and a ring may beformed between Ar₁₂ and Ar₁₃, or Ar₁₂ and R₁₂, or Ar₁₃ and R₁₂:

wherein Ar₁₄ and Ar₁₅ independently represent an arylene group having 6to 30 carbon atoms; and R₁₃ and R₁₄ independently represent hydrogenatom, an alkyl group having 1 to 20 carbon atoms, or an aryl grouphaving 6 to 30 carbon atoms:

wherein Ar₁₆ represents an arylene group having 6 to 30 carbon atoms;R₁₅ and R₁₆ independently represent an alkyl group having 1 to 20 carbonatoms or an aryl group having 6 to 30 carbon atoms: and a ring may beformed between Ar₁₆ and R₁₅, or Ar₁₆ and R₁₆, or R₁₅ and R₁₆.
 5. Anorganic electroluminescence device comprising a pair of electrodes of ananode and a cathode, at least one of which is transparent orsemitransparent, and at least one layer of an organic material formedbetween the electrodes, wherein the organic material layer contains thehole transporting polymer described in claim 1 or
 2. 6. An organicelectroluminescence device comprising a pair of electrodes of an anodeand a cathode, at least one of which is transparent or semitransparent,and a light emitting layer formed between the electrodes, wherein thelight emitting layer contains the hole transporting polymer described inclaim 1 or
 2. 7. The organic electroluminescence device according toclaim 6, wherein an electron transporting layer containing an electrontransporting compound is provided adjacent to the light emitting layerbetween the cathode and the light emitting layer.
 8. The organicelectroluminescence device according to claim 6, wherein the lightemitting layer contains a light emitting polymer, which contains arepeating structural unit represented by the following general formula(21) in the proportion of 50% by mol or more based on the totalrepeating structural units and has a polystyrene-reduced number averagemolecular weight of 10³ to 10⁷ —Ar—CR═CR′—  (21) wherein Ar representsan arylene group or heterocyclic compound group having 4 to 20 carbonatoms, which take part in a conjugated bond; and R and R′ independentlyrepresent a group selected from the group consisting of hydrogen atom,alkyl group having 1 to 20 carbon atoms, aryl group having 6 to 20carbon atoms, heterocyclic compound having 4 to 20 carbon atoms andcyano group.
 9. An organic electroluminescence device comprising a pairof electrodes of an anode and a cathode, at least one of which istransparent or semitransparent, and a light emitting layer formedbetween the electrodes, wherein a hole transporting layer containing thehole transporting polymer described in claim 1 or 2 is provided adjacentto the light emitting layer between the anode and the light emittinglayer.